Uh...
Tbh, depends.
In general, it's best not to collect until a number of days inactive, and bills can be advantageous to only pay just before collecting.
To go into more detail, I'd pretty much have to write a guide, and CBF doing one right now :P I'd suggest joining an alliance and reading their guides (if you are already in an alliance, dig up their guides; if they don't have up to date ones, I'd suggest finding a better alliance)