What to do with a 10gal tank

So I have my 60 gal ready to start. Which leaves the question what to do with my sometime soon to be fishless 10 gal? I wouldn't mind making it into a nice betta retreat but... I read a lot about quarantine new fish first and with my 60gal tank now that would be probably a good plan. Its gonna be a little tough because I cant get comfortable with the thought of leaving it empty in between quarantines. Which also raises another question: how do you maintain a quarantine/hospital tank? Do you have some fish in it to keep it cycled and running in case you need it fast? Or just start it running when needed with filter media from an established tank?

That is a very valid question you have there.
Personally I have had a quarantine tank for a couple of months and never used it. I'm not sure about others but I prefer having an extra empty tank just in case.
If you can't stand having an empty tank, I'd suggest making it a betta tank! I'm a bit biased tho because I just got one.

Quarantine Tanks

I think my experience with quarantine tanks is generally when fish need to be isolated from the main tank. This can be because of fighting, injury, sickness or breeding/ready to deliver young. In all these cases the time spent in this isolation tank can be from a few days to weeks.

"Quarantine" is not the best name for the purpose of the tank as it has an attachment to disease or holding new fish before they are introduced into the main tank. In any case, the tank still needs to be cycled in order to function. The tank does not need to be empty in between uses; it can house fish, plants or even snails, as long as you can move the inhabitants to another container when you do need the tank. I like the idea of housing plants and one or two fish. The fish and plants can be transferred to the main tank at any time.

In my case I rarely use quarantine tanks since I generally do not purchase store bought fish. For most, store bought fish is the main source of livestock and having a quarantine tank makes sense during the time that you are introducing new fish. It will takes a few weeks for disease to show up so the tank needs to be cycled and fully capable of supporting a group of fish. After the holding period, you can still use the tank, with plants taken from the main tank. How often the tank is used will depend on how often you are introducing new fish. If you have fully stocked your main tank, then you can dedicate it to another purpose.

I keep one 5g in reserve and it is holding live plants, snails and a single Dwarf Pygmy Sunfish. It is fully operational and so can be used at a moments notice. I do not see it being used as a quarantine tank since I rarely bring new fish from the LFS, but I do see it as a good tank for small fry etc.

Hope this gives you some ideas