FS Nollie Nosegrind: This one is pretty intuitive on a small ledge. If you can nollie fs 5050 it very comfortably, do the same thing, but keep your weight a little more over the nose before you're about to get in and put some weight on your front foot. Once you're in, balance like a nosemanual and pop out. For some reason, I find it much easier to get a nice pop out of these than a regular fs nosegrind.
FS Nollie Noseslide: Go at slight angle, do a straight nollie at the ledge and then turn slightly (late and not too much) and you'll lock in. If you're sticking, then you're either turning the board too much, not pushing on your front toe, or your body is too twisted causing the nose to jam. Keep in mind the fact that you only really need to turn about 45 degrees, not a full 90. If you're sliding and shooting out, just lean into it a little less, or turn less. It may also help to imagine doing a nollie front crook but missing your truck, that sometimes works for me.
BS Nollie 5-0: This one is much easier than a nollie bs 5050. Roll up to the ledge at slight angle, look at the ledge. As soon as you pop, turn your head and look at your back foot which should have slid to the tail already and put it down onto the coping. It'll require a shift of your centre of gravity from the front/middle of your board to the tail end but its no different to a nollie fs 5-0 in that regard. The only tricky thing is rolling up, popping and then instantly turning your head to look at your back foot so that you can aim the truck.
BS Nollie 50-50: Once you can nollie back 5-0 you can just cheat by doing that and putting your front truck down. But to do it properly its a bit harder. Its a lot of commitment. Going faster, popping earlier and making sure you level out the nollie so both the front and back truck are high enough before locking in is pretty important. Like the 5-0, you also roll up looking at the ledge but as soon as you pop, you'll want to square off your head n shoulders so that they're parallel with the ledge.
BS Nollie Noseslide: Might help to practice this one but just going straight at the ledge and nollieing into nosestall, then gradually decrease the angle. Gotta go fast and pop really early. Make sure you level out the nollie. The general tips at the bottom apply especially to this one.
BS Nollie Lipslide: On a low enough ledge this is pretty much a kickturn. Upper body motion is pretty much the same as the nollie back 5-0, but obviously gotta whip the legs around a bit more.
BS Nollie Tailslide: Upper body motion is the same as the nollie back lip, but like the nollie back 5-0 you want to shift your weight from the front/centre of the board to the tail as soon as possible before you aim your tail onto the ledge. I guess it's kind of a nollie back 5-0 and nollie back lip combined, though neither of those are necessarily a prerequisite.
General: For most of these tricks you'll want your front foot in the heel side pocket of the nose, sometimes it helps to point it forward a bit. If its a nollie trick that involves getting the nose over the ledge (noseslides, nosegrinds, 5050s), make sure you don't keep your weight fully over the nose the whole time, or the nose won't come up high enough since your whole body is over it. A common symptom is the nose hitting the ledge on the way up and not making it on top of the ledge. A bit of see saw motion from leveling out your nollie is necessary. Rocket nollies won't cut it.
As long as the ledge is a reasonable height, the nollie in shouldn't feel like a heavy brute force effort, but rather a light, nicely timed pop. Be conscientious of leveling out the nollie with your back foot and lifting your front foot up into the air while keeping your weight off of the nose so that the nose can actually come up before you get into the trick.