My vote is for Lather Bowl... I prefer at least a 5" opening, and fairly shallow. I like to bowl lather, but can't stand the 'clank' sound made by the brush hitting the sides of something too narrow. That's just my opinion. A textured bottom also assists in generating lather. You would be surprised how many bowls and mugs can be found in the wild that can be re-purposed into shaving gear. Etsy is also another good source for some nice hand-turned pieces of shaving pottery. Enjoy your search.
I've got a cheap white $2 ceramic lather bowl I bought in a supermarket. It fits in my hand perfectly, it's about 5" across, and has a small pedestal bottom which helps to hold on to it. Kind of like a rice bowl. Works great for soaps or creams. Mugs are usually used just if you keep your puck in it. If you face or bowl lather, most people just load off the puck, I think. I'd reccomend grabbing a coffee mug and a cereal bowl you already own and try all the methods out.
My approach: Bowl (or scuttle in my case) if I am bowl lathering. Mug if I am face lathering but want a place to keep my lathered up brush between passes. If I face lather I use a stick or load from whatever tin/tub the soap is in.
Georgetown G20 scuttle for both soaps and creams. I used to use a lovely bowl from jays clays on etsy but warm lather is fantastic and I now use a scuttle everyday for bowl or face lathering
Mug. Used to use a bowl until I shattered mine. Now I need a handle to hook my thumb through. I have a giant latte mug from the dollar tree that I use like a bowl.
I have one mug that I load my Williams in. Otherwise, I load from whatever container they came in. I build my lather on the face. Saves time, exfoliates skin, and easy clean up.
Prefer a mug. That's what Dad used and for some soaps still use. Hard soaps like D. R. Harris use a bowl. Others have stated not liking the clank of the brush handle against the sides. In the end get something that you will enjoy.
I use mugs to hold soap while loading the brush, then move to either the face or a bowl to the build lather.
I recently put together this contraption to act as a scuttle. It is a large soup cup with a pet bowl that just fits in the top. Hot water goes in the bottom. I have used it only once, and it performed pretty well. I am a face-latherer, so I will probably use this only on special occasions. Edit: I forgot. I paid $2.50 for both pieces at the Goodwill store.
Pfaltzgraff 14oz. Soup Mug Approximately 5 inches across and 2.5 inches deep. I Love it, and use it for soaps and crèmes. Everybody's different, but I like to use a bowl because it's what I learned to lather in when I was new to wet shaving. I'm not so much a noob anymore, but I prefer to use the bowl yet today. It just suits me. I can face lather, but I find it much easier to get the lather right when I'm looking at it. I use this bowl to make test lathers in. When I get a new soap I usually make 5-10 test lathers in a row to figure out how much water it likes, and which type of brush works best. I don't recommend that anyone ever try to do 10 lathers in a row on their face. (you'd only do it once.....) If a soap proves hard to lather, (MWF, or Williams) the bowl is the only way to go until I really get that soap mastered. Whatever your choice, Happy Shaving!!
If my bowl wasn't plastic this would have happened to me several times. I have been meaning to look for a cheap cappuccino cup to try. I like containers for soaps with lids, but bowls for lathering. Also +1 on looking around locally to see what you like for cheap. Then decide if you need/want something shaving specific.