When you buy for yourself, the question is not what is beautiful. It is what is missing from what you already wear.
Most people are short one good everyday piece and long on occasion pieces. Look at what you reach for on an ordinary morning and what sits in the drawer, and buy toward the first group.
How do I choose something I will actually wear daily?
Pick the piece that would go with what you wore yesterday, today, and tomorrow. A chain that layers with what you own, or earrings light enough to forget, will be worn far more than anything you have to plan an outfit around.
Is it worth buying something a little nicer for myself?
For a daily piece, yes. It is the one item that gets the most wear per dollar. Spend on the thing you will put on two hundred days a year, not the thing you will wear twice.