I went through a big thing a few years ago replacing exterior teak with Trex. The remaining teak is portable and comes home for refinishing - drop boards, tiller, trim board at the aft end of the hatch slide, dorade covers, lazarette hatches. Worst was the top of the tiller, which I had to take to bare wood.
Tried using the old can of varnish, but it had seen it's day. A fresh quart of Minwax Helmsman Spar Gloss was a delight. I just wish HD sold it in pints - I'd save a bit on discarded stale varnish. But no sense fooling with the old stuff.
Basically used 120 grit to even things out, then applied a first coat. Large flat surfaces responded well to the random orbital sander with some 320 discs I found at McMaster Carr. Tried something new before the final coat - one of those sanding sponges (v. fine grade). Best thing about them is you use them wet and there's no dust - just some white mud that you sponge off. I think I'll have to try some of the coarser grades in the future.
Next refinishing job is probably the engine. I've had a 'phantom' sea water leak for two seasons that I finally found and corrected. But the engine below has suffered and needs attention. I've got to strip down one side of the engine (distributor, alternator, starter), wire brush it (angle grinder), prime (Interprotect 2000 epoxy), and paint (gray).
Gee, might even have time for some electrical work. I'd like to replace my old Perko switch/fuse panel with something having more circuits. In 25 years with the boat, I don't think I've ever replaced a fuse. Perhaps they don't need to be 'front of panel' accessible. I could bury them behind and make room for more switches. I currently have 6 but have double leads to some switches, and would like room for 12 - something to work on.
This may be my first year wintering over in the water. My yard uses a crane for hauling, and either puts boats on jack stands or puts them into a cradle on a trailer, then uses the trailer to move them around in the yard. Last Fall during hauling, the crane dropped me into the cradle - damaging the boat, the cradle, and the trailer. The cradle, although designated for my boat, belongs to the yard and has yet to be repaired. Yard doesn't have room or stands to store me on jackstands (never seen the yard so full - hope they all pay!). Owner says he'll give me a 'bargain rate' to stay in the water. Several other boats do the same, so I ask - why not me too? He'll give me a short haul in the Spring (when he has room) to do the bottom - what more do I need?