Im assuming you have copyrights to your material and its not super complex

There are several ways to go about this depending on our distance from each other. If you have an existing idea or complete song (it doesnt have to be perfect) and can send an mp3 to me I will have a listen to it and see if  I can add a quality bass line  to it. Then I can send it back to see if it is something you like and move on from there. 

Maybe you might know what you want already but, you would rather have a bassist play it. I can work with that.

I can play it at my place on my gear and send the wav file on a disc right to you and you can drop it in your software. There are some ways I dont like to work and I will add to this list as I experience them.

(1) I dont like to go at things with no prior knowledge of the material. I doesnt allow me to get a feel for the groove a lot of the time. Sometimes its not a problem but, I would rather not waste time finding out. Unless of course you are paying me and dont mind.

(2) I dont want to listen to somebody telling me do this riff 4 times that riff 3 times and so on. It gets old fast for me and I hardly remember riff 1 when it comes back. It may sound lame but thats how I am. Now if you want to pay me to do that no problem.

(3) I  dont want to deal with people that are totally fucked up intoxicated. While I am not against being that way it usually does not help in the studio.