You should know...
Watch your ratios!
Keep your ingredients' ratios accurate;
it'll be easier to identify mistakes, but even better, you'll be able to
tailor your future bread to closer match the banana bread that exists
in your mind.
Mind your baking pan!
The size of your baking pan is going
to affect your cooking time: is more of your batter touching more of the
pan? You'll probably want to leave it in the oven less, and vice versa.
Be flexible when using extra ingredients!
Larger additional ingredients like walnuts, yogurt, chocolate chips, etc will
affect your bread. Stay flexible and listen to your gut when it comes to adjusting your ratios!