Most of the time I am having a "hard" time deciding where to place my Kickdrum and Bass frequency wise.
Either the peak of the kick is, depending on the tune of the track, somewhere from 70-130hz and the Bass gets all the spectrum below.
Or, I'll try to let the Bass use up the Area from 70-250hz something and the Kick gets all the Space below.(and a klick or something in the mids to be better recognized.)
I mostly like both options nearly equal and can't cant always decide which one to apply to a certain song.

How do you decide this? Do you decide early in the Progress? Or do you just sidechain bass/sub frequencies and dont care about it? Which Genre/Arrangement/Set of Notes suits better to which approach?
(The only thing where its clear to me is trap where the kick always uses the sub, but I don't produce that^^)

 

it depends on the type of music youre making and ultimately what you want. Boomy kicks or boomy bass?
I use a combination of both sidechaining and eq to cave out a place for my boomy kicks.

 

Go with offbeat bass so you don't have to worry about this! :P
Serious answer: it depends A LOT on the genres, and the kind of bassline you got. So many variables: sound of bass, sound of kick, notes, frequencies, etc.

 

This is one of those things you just choose based on experience and just general flow.
If you dont get it right at the beginning then you can still replace the kick later, kind of harder with the bass since a lot of the flow, mojo of the song is sometimes based around it.

 

Use a reference track than...
You cant go wrong with a decission thats allready made and sounds good

Thats what i do if i cant decide.

Depends on the genre. If i decide on my own.