If it is going on skin: clean and dry, nothing underneath. No lotion, no oil, no sunscreen under a jewel or a glitter. The adhesive is not the problem when this fails, the barrier is.
If you have never used loose glitter: start with a gel. It places where you put it, it does not travel, and it is a much shorter route to something that looks deliberate.
If your skin reacts to things: cosmetic grade only, and test it first. Craft glitter is sharper and not made for skin. Put anything new on an inner arm a day ahead rather than on your face an hour before you leave.
If it has to survive a full day: jewels outlast glitter. Press each piece and hold it for a few seconds rather than tapping it on, and carry spares, because the ones that come off do it early or not at all.
If it is for photographs: chunky and holographic over fine shimmer. Fine shimmer reads as nothing in daylight. Larger flakes and placed stones catch light from an angle, which is how they show up on camera.
On getting it off: oil-based cleanser, not soap. Soap pushes glitter around and leaves adhesive behind. Oil lifts both. See accessories for the rest of what finishes a look.