How do you allocate how much of your savings go into your TFSA, RRSP, and now FHSA?

Hey guys, I'm 30 years old, no debt, making $88k before tax. I've had some automated payments going into my TFSA and RRSP for a while but now I'm thinking I need to be more strategic about where my savings are going. I know the general advice is to max out the TFSA but I'm not sure how that's done when the amount available to put into savings isn't enough to do that? Hypothetically lets say I have $1500 at the end of the month to put into these accounts. How do I know how much to put in where?