I usually center my axles with loctite and use a q tip to avoid getting it in the bearing, i also glue the bearing to the yoyo so it doesn’t fall out, so i do not lose it. Lots of yoyos come with axles that are too short or stainless axles that come loose easily, most hardware stores have small metric and sae studs that use hex wrenches to tighten it. the black steel ones work best for me, I would just upgrade to a metal drifter or some other yoyo with the same bearing size that is made of metal (duncan metal drifter is usually sold right next to the speed beetle at toys r us) or order a higher performance and quality yoyo online… you don’t have to spend 100 dollars, there are well playing metal yoyos for anywhere from 20-50 dollars, lots of good ones r in the 35 dollar range, but some shady places online can sell yoyos that play well for 10 dollars but can take 3 months or more to ship sometimes, it can be a gamble if ordering from some places overseas.
and learn a bind if you haven’t already because a yoyo loose enough to need a bind should sleep longer than a responsive yoyo with no effort once u mastered a good throw. Also experiment with spacers to find the widest gap u can use and still get the yoyo to come back in a bind. Then practice a good winding technique if you haven’t already so that you don’t spend most of your time wrapping your string instead of yoyoing.
after you have done all that you will learn new tricks naturally, and with the internet you can learn more than just the basic tricks in the trickbook it comes with.
after you have broken a bunch of yoyo’s collect all the spare axles and bearings and then try to make a homemade yoy… that is if you still feel like it, but modifying existing ones will probably give you better results, and learning experience if you ever do make a yoyo from scratch, after all there is a lot more yoyo company’s around now then i can remember 20 years ago,and they had to start somewhere… lots of the companys have also came and vanished too.