Testing Copper Supply Lines before hooking up

Hey everyone, I've sweated about 20 joints - I'm t'ing off the cold & hot water in the bathroom that previously had one sink and will now have two.

I've got everything done, but would like to test the joints (and my sweating abilities / inabilities) before hooking up to the supply lines, because if I have a leak(s) I'll have to disconnect, drain, resolder, connect again.....

Let me know any tricks of the trade, thanks!

for a small system like that, I usually just turn the water on and go for it...
For a larger system, we pressurize it with air and look for pressure drop and, if needed use soapy water to find leaks...