I used my history of woodworking to tackle repairing a window over a bathtub! Yes, it had a shower, which, having been used by my son for over 20 years with very little attention from me, had the sill nearest the shower rotting from loss of paint and water splashes. (Does anyone else ever remember a window in a shower?)

   I could have spent $300 or more having an 'expert' take the entire thing apart and replace everything, but I am cheap.... so I then intended to just pry out the old window sill and hope lumber yards could still match the 60 years old basic size. Then Winter intruded, and as it warmed up in March, COVID intruded.... so I cut a 3" piece of the sill out and looked for some wood I might used to make a vaguely reasonable replacement. There was some Maple... but sheesh! Way too hard to work. Then I discovered a length of Teak I'd had for 20 years that was salvaged from surplus after some Indonesian fishermen spent 2 weeks building 2/3 of a Teak fishing boat for the Smithsonian Folk Festival....

Eureka! It was long enough by almost 1/4 "...and water resistant. I'll spare you several paragraphs about myriad cuts on the table saw, grinding an old scraper blade to the right contour, scraping away the saw cuts and sanding it forever. Anyway, I now have a Teak window sill ready to install... after I finish replacing half of the external base of the window frame which had also rotted at the same end.
I suppose I have 10-12 hours of mumbling and cussing in it so far..over 3-4 weeks. But the only cost was for some paint and caulk... and it kept me away from cheap bars during the lockdown............ of course, I didn't go to them BEFORE..

If the last steps go ok, I'm gonna be way too smug.....