Collecting. Collect everything. But heres the trick, drop them in your house in a place you will see them when entering = visually satisfying. You're not going to get much out of storing them in a cupboard. In breezehome i have a big pot of gems and soulstones that im filling up, it really inspires me to play more and collect. A house full of treasures.
Dragon fights getting repetitive? Collect the bones and scales, store them in your house. Next time you fight a dragon you'll want to kill it, to simply collect the bones.
Dungeons getting boring? Pick up, for example, skeleton skulls (Pick an item that interests you and make a note to pick them up)
Pickpocketing got old fast? Collect the rings and gems you pickpocket and store them. Drop them in a basket or cauldron.
Too many potions? Drop them in your house in a pile, and add to it as you advance in the game.
Theres nothing more satisfying to me than walking in my home and seeing my shelves stacked with all sorts of interesting items. And piles of gems.