Our bass player and I were talking a bit about locking in and which of the bass guitar notes I would match with the kick.  It got me thinking about the whole idea of locking in with the bass player.  I doubt there is a magic formula but if you know of one, please share it   It seems to me that sometimes when we (bass guitar and drums) are locked really well, I'm not matching every note they are playing, just some special ones.  Othertimes, we are playing almost note for note. So as with much of what we do, there isn't a simple rule. I assume folks fall into one or more of these categories....

1. work this out with the bass player for each song section
2. just play what seems to feels good no matter what they are playing
3. follow the bass player and try to fit in
4. tell the bass player what to play
5. bass player or leader tells you or writes out what to play
6. Mathematically analyze all the permutations and run them through your funk optimization filter

I've mostly followed the bass player and tried to fit in.  In one of our original songs, the writer (keyboard) scripted the bass pattern and I do it verbatim - and it's a good one.. Sometimes when playing with a less experienced/skill player, I have to dictate the groove more assertively but that usually gets dicey.  Just curious to know how you guys approach this...

I start out just listening and experimenting, usually starting with the simplest possible groove. Then the bass player and I may discuss it, or work it out through eye contact and nods while playing.

And sometimes the boss will tell you what to do. Sometimes Clarence will catch my eye, then pound his fist on his chest like a heartbeat, letting me know what kick pattern he wants to hear.

Whatever works!

Ive always tended to play more off of the guitar player with the bass player in mind. Rarely is it note for note but if its what grooves best?....im on it.

 
I think I'm lost without a good bass player. And I hope the bass player is lost without me. We don't always play the same rhythm, but we always keep together on the accented notes. And when I accidentally get lost in a fill, the bass player's foot tap or nod always gets me arrive back on time.
 

I am the exact same way. Part of that is because I have so rarely played with a good bass player but some of it is because that is just what I prefer to do. I also play a lot off of the vocal lines as well.

The other day members of a band that I play with told me that I shouldn't have any contact with them, I should just play as I was a metronome - but this is crazy, I would really need that eye and ear contact...
 

Keeping it simple and keeping the sonic "mud" out of the sound.

It can be tough to coordinate the bass g, rhythm g. and drummer.

Keeping it simple is the way to go.  Also an understanding of which instrument will take the "onus" of the phrasing is cool also.  I would not want to step all over a good bass or rhythm guitar part and vice versa.

Bass guitar can be tricky to hear sometimes also and when you can hear it it usually means it's too loud!  I prefer a bass player that knows how to eq his rig and also one that is a team player.  It's also nice if they can count, keep time and don't fight your tempos- good or bad as they may be at the time.   

One thing I've learned to do is keep good eye contact with the entire band, but the bass player is my main man. No matter what the other members of the band do it's up to both of us to keep each other solid with the beat. I always use my ears and listen, but it's the eye contact between the bass and drums that "drives the music". Then it's the eye contact with the entire band that ends the song. You'll find that "eye contact" is crucial when playing at a jam, especially for endings. There's two key words used at a jam, both "look" and "listen" apply when playing with unrehearsed musicians. If both the bass player and drummer aren't solid together, the resulting music will fall apart.

As with most things it's a collaboration.
I tend to veer away from busy bass drum parts, so I listen to what the bass part is and try and pick out an overall feel I can emphasise with my bass drum.
Like Mr A, I start simple and add something if it needs it, or if I'm asked to.
In the end, most of the time the bass drum part will mirror closely the bass part, but not always. I've played on some songs where the songwriter has requested a bass drum pattern that plays in all the places the bass isn't  and it sometimes works a treat!

Same in my case.

I use to build my kick part on the guitar and/or keyboards (I listen to the guitarist and/or kbds player and play my kick just the way I feel good, -- or, if you want, with the kick I play their accents the way I hear them in my head). The bass player uses to look at my pedal beaters to understand my idea, and then builds his part around it.

However, this does not mean I won't change my part later because I feel it necessary or because the bass player comes up with some 'modernization' I like to support.

Also, at times the bass line plays more important role (than other instruments) in a given musical peace, and in this case I play the bass accents the way I hear them, while guitar and keyboards have to bend if necessary.

Starting simple gives you more expressive headroom.

Locking in does not imply bass and drums are playing the same notes.  Each could be off in their own world and still be locked in because everyone has the tempo nailed, as well as the 10,000foot view of the song structure, i.e. verse->chorus->etc->bridge. 

All members transitioning song sections, together, in a manner that supports the music is what locking in is all about.

An experienced bass player will have their high and mid frequencies dropped out of the mix so as to eliminate muddiness or stomping on other instruments frequency envelope.  I say experienced vs. good because there are killer bass players that do not have an understanding of frequency and how instruments interplay.  This does not make a poor bass player, but rather just some person who does not have experience in this area.  Understanding each instrument - in your bands - frequency envelope and adjusting your instrument around this is the first step in making the band sound clean.  Forgive me if I'm stating the obvious.

You could get together with your worship leader and bass player and suggest they work as a team.
Why not seek to improve, rather than living with the status quo?