For the first time finisher, I would get a quart, or smaller amount of the satin finish. I believe quart is the smallest. It is a tung oil and resins finish, and is very forgiving in its application.

I would start with applying a coat of the finish and use 400 or 600 wet dry sandpaper to sand over the wet finish to make a slurry of wood to help fill the pores and smooth out the finish. Lightly wipe the surface down after the wet sanding, leaving a very thin coat, but filling some of the pores.

Then with a soft material scraper, I lightly squeege the material off. Then let it set, and do not be worried about getting a smooth finish yet, what you are doing is filling the pores of the wood. By lightly wiping the surface with a soft scraper, I keep the surface clear, and I'm starting to fill the pores. I apply three or more coats and let each coat set for 24 hours. I can now surface sand with 600 or higher grit and water, being careful of sanding near edges, and just lightly touching up where needed. (Where needed, not the whole uke).

Now that you have the surface filled, you can use a foam brush and lightly apply a smooth coat and let it dry again at least 24 hours, lightly sand between coats with water and 600 grit sandpaper. Keep applying coats until you're happy with the finish.

I usually stop after just a few coats on the soundboard, but I put a few more coats on the back, sides, and neck.

Waterlox leaves a wonderful deep golden brown tone over the mahogany.

It will take about two weeks for the final finish to cure. Then you can start to hear the real final sound develop. This last photo shows the wood with three foam brush applied coats, making six coats total.