Is there a proper way to fill an electrical panel?
The main thing is to watch your stab limits.   Breakers clip on to panel parts called &quot;bus stabs&quot;.  They have a practical current limit, often stated on the panel label.
Some people get it in their head &quot;put the biggest breakers up top&quot; (as if to reduce the few inches current must flow down the bus, as if that matters).  Then they fit a 100A breaker opposite a 50A breaker, and voilà, they have put 150A on the bus stabs in the first two rows.
Also beware of &quot;double-stuffing&quot; panels - lots of people get the 'bright' idea to save themselves the cost of a pizza by getting the smallest panel they can.  Then they either choose from the outset, or are forced into later, going with &quot;double-stuff&quot; breakers that put 2 breakers effectively in 1 space (or 2 240V breakers in 2 spaces).  I recently saw a setup that had a 40/40 quadplex across from a 30 2-pole.   The person wanted to double-stuff the 30 to a 30/50 to feed a subpanel.  Notice a problem? You now have an 80A (40/40) breaker across from an 80A (30/50) breaker.  Stab limits again!
Go big. Go really big. Spaces are cheap.  Regrets are expensive.