Something which took me a year and a half to add, but now I wish I would have done immediately was add a quick change tool post (QCTP). Aside from making it super easy to switch bits, it also lets you dial in the tool height exactly without having to use shims, and will keep that height dialed in. It just makes the lathe so much nicer to use. I went with a A2Z CNC and TS Engineering clone for $60 off eBay. It mounts to where the old tool post mounted. I chose to use a threaded rod with the stock handle one it to mount mine instead of the included bolt, since this way I can easily rotate the tool post, which is necessary anytime I change the angle of the compound slide. Really, the biggest downside is now I want tool holders for each tool bit I use, and that adds up quickly at $20 a pop.
By the way, I like to center my tool bits by turning the end of a piece of rod to a point. It's easily to tell if the created cone shape comes to a point or is actually flat tipped.