Skill ability won't level up

Skyrim is really similar to the previous Elder Scrolls games. Leveling up an ability increases it's effectiveness but won't be very noticable until later levels. Perks however give the ability a noticeably significant increase. The higher your magic skill
is, the more effective and powerful the spell will be in that particular mage ability like Conjuration, Destruction, Restoration, etc and it will use less magicka. You won't notice much of a difference going up one level here and there in your magic skill
but once after you've raised the ability quite a bit is when you will start noticing the difference. So just keep working and raising the skills you want, it is working. Just takes some time.

When you level up your character as a whole, not going in to improve a single skill, you press b and press up for skills and you are prompted to increase magicka, health or stamina before taking you to the ability constellations. Choose stamina to increase
it

The problem I have with followers is that they don't level up. There is a
long discussion at uesp.net, but the conclusion seems to be that most followers won't level up with you, some of them will level up some skills but not others (and not always the correct/most useful skills), and some (Dark Brotherhood) seem to level up
properly.

Make sure you are not trying to level up skills that are already at 100. They won't count towards your overall level. Example, if you have 100 for Alchemy, making more potions will not help improve your overall skill.

They won't die; I use them to level up my skills. Beat them down; then heal them to level up your restoration. You can level your block, one-handed(not enchanted),etc.