When the fee rate is low https://mempool.space/

Also, when you do deposit Bitcoin into it, make it a decent sized wallet amount ($100 or something) and then swap out with https://fixedfloat.com/ or something if you don't actually want that much in there. This will make sure your channel is a decent size for inbound liquidity.

Don't forget to check out blixt as well if you don't mind fiddling with settings and things.