[Holy cow; just looked @ this thing & must apologize for its length, especially when it could be described then demonstrated in well under a minute. Using words to describe properly a manual skill is frustratingly inefficient; worse yet when there's no immediate feedback & potential risk exists. Anyway, I think I've got it right, finally.]
Photon,
Don't think I saw anyone mention this (my bad if I missed it) but it's hard to cycle the slide because you're compressing two springs simultaneously: the one that returns the slide to firing position (back "in battery"); also the hammer spring (which produces hammer strike impact). I'm assuming this to be an "administrative" function, i.e., shooting @ the range or some other situation where the extra time spent means nothing. Simply split the job into two: **** the hammer first — maintaining muzzle discipline (pistol pointed downrange or in a safe direction). Mandatory behavior: you MUST keep your finger straight, outside & above the trigger guard. Remember, the action you're drilling will make a pistol ready to fire. Your finger should remain off the trigger until your sights line up on a recognized target. Start watching TV/movies & see how many of the actors' fingers go onto the trigger as soon as they pick up their movie "weapons". Now, check the pix of Marines & soldiers in the news. No matter how uncomfortable the position may be while holding their rifles, you'll see fingers visible outside the trigger guards. Professional. (If in doubt, look to the pros.)
Don't know how you're cycling the slide now, but this may be a better method. Hope I can manage to describe clearly in words a manual skill. Rather than use conventional training terms (strong side/weak side), I'll assume right handed use. Important point: if you don't do this @ a gun range, two things are critical; always, always observe these. Positively absolutely ensure the pistol is unloaded: magazine removed & chamber empty. Both look (mag well & chamber) then feel w/a finger (same two; mag well & chamber). After all, you may have to perform this in the dark, right? Hey, we may have great lights here on CPF, but turning on your megalumen Surefire searchlight while you work on your pistol is NOT A GOOD THING... ;-]
Now, leave everything except the pistol — the loose round (from the chamber, if it was loaded), the magazine & ALL live rounds in a one room. Go to a different room & identify a structural wall (e.g., the "safe downrange" direction; something that'll stop a bullet if you screw up). Permit no live rounds in the room w/you. Be rigorous & disciplined about this. Follow it every time you practice & those accidents will occur to someone else. (Those "accidents" are, nearly always, more properly classified as negligence. Carelessness. Or stupidity.) Gun handlers need to have a Zero Defects mentality, procedure-wise. It would be much better, also, if you have an experienced gun handler watching you. Following a list is not the ideal way to master a manual skill. Anyway, the steps of procedure:
Point downrange, pistol held in your right hand about shoulder level, a foot or so in front of you. (Never hold @ waist level. Looking down is a VERY BAD THING in a threat environment.) Realize that, under stress, you will revert to whatever you've practiced, good or bad. Do it correctly from day one. Allow your peripheral vision to pick up changing threats — even if you have to look at the pistol — by maintaining high line-of-sight. With proper practice, you'll routinely perform this w/o looking @ the pistol: fingers are working, but you're continually scanning your surroundings.
Regarding the cocked/uncocked hammer, you can try it both ways. You may find that, w/the proper procedure, you're able to cycle the action starting w/hammer down.
Cup your left hand, fingers & thumb together, & bring this hand forward, over the top & down onto the rear of the slide. ALWAYS bring your free hand onto the pistol from its rear, closer to your chest. Always be respectful of the muzzle; your manipulating hand must never stray near it.
I don't know the Keltec, but presume it to be a small pistol from the small caliber. Realize that a correct left hand grip is more difficult w/a "pocket pistol" simply due to its small size. The pads of your fingers should press on the right side of the slide, behind the ejection port (the cutout where empty casings are kicked out). The heel of your left hand should press onto the left side of the slide.
(Note: your fingertips should always leave the ejection port clear. Your grip — to cycle the action — should always be the same. Now, w/an empty chamber, there's no consequence if you've trained carelessly, allowing yourself to block the ejection port. Later on, clearing a malfunction, properly cycling the action becomes a critical skill. Flawed technique could prevent you from returning your pistol to service in an emergency. Or, if you stick a finger inside the working parts, you could wind up w/a finger being "bitten" by your pistol; never a fun thing.)
Squeeze firmly w/left side fingers then do a push/pull w/your arms. Your right hand arm should push directly forward towards the target(more on gun side arm position in a moment) while your left pulls back. Do not release your left hand; allow it to slide off automatically by using a firm (not fierce) grip. Follow-through helps in many sports, as it will here. Your right hand/pistol should not extend completely straight. Your left hand should open then lightly slap the upper right side of your chest. If you picture the lines of movement (std clock orientation here, 12 o'clock is straight ahead, to target; watch your six means check your tail, etc.), ideal would be right hand pushing towards 12; left moving towards 6.
(Additional safety aspect: slapping your chest ensures your free hand won't float out in front of the muzzle of the now cocked-&-loaded pistol's muzzle. If you practice your cycle-the-action movements which leave your free hand near the pistol, you're training a risky behavior which is a dangerous habit.
Dangerous behavior note, which could be a threat to you @ commercial ranges:
Be very wary of shooters who have trouble cycling the action. You've probably realized already that anyone can exert more strength (in this situation) by doing two things: moving hands closer to the chest & pushing across your body w/both hands (as opposed to the push/pull toward & away, which I've described above). You'll see shooters w/little upper body strength (right handers, here) who resort to swinging the muzzle to their left. It makes it easier to cycle the action this way (right hand now pushing towards 9 o'clock; left hand pushing to 3), but it's somewhat disconcerting (!!!) if you're the unfortunate shooter who happens to be standing to the left of this incompetent. You may be covered by the gun muzzle. I'm probably on my second hand, counting the # of times I've had to dance backwards off a firing line because some moron did this. After all, if they can't properly perform this most basic skill, who knows what they'll do next? (Guarantee you'll get the rangemaster's immediate attention if you do this. They do get excited when someone violates procedure.)
The push/pull is not a violent, uncontrolled action. Absolutely crucial point here: your trigger finger MUST remain straight, outside the trigger guard as you push forward w/your right arm. Again, this sequence chambers a live round, so once the slide moves forward, chambering a live round, your pistol is now hot.
Now, return your left hand to your shooting grip (the push/pull of a Weaver type, I expect). Once again taking care that you move this free hand into your firing grip from the pistol's rear. Remember that, w/a tiny "pocket pistol", it's far easier to violate good muzzle discipline.
Final thought: feel free to practice w/empty hands initially: right finger pointed out from a fist; left cupped above the right, then moving back to slap your collarbone. Then move on to the empty pistol, only loading when you're competent. You achieve speedy competence by going correctly but slowly first, then increasing your speed. Happy shooting.