FIRST OFF,
the first rule of beat club: there are no rules.
second rule of beat club? make your own.
ok, now, seriously. that is to say, there are no rules in doing this, but everyone has their own methods. you really have to go with what you feel comfortable with. are you playiong keys or sampling? when i sampled, i would get the sample and get my chops done first- figure out the tempo, time signature, etc.
realistically if you have a good melody line in your haed, you want to get it out before you lose it. record it and then play with a drum line till you got something that fits. that makes sense if you have a melody. if not, you may think about the style of track- you want to make something intense? uptempo? melancholy? you can do drum lines that fit these things and then play to that. much of the energy/direction in a beat comes from the drums- hi hat patterns especially. you can do a simple 1-2 kick pattern and experiment with the hat patterns and hat sounds. The earlier you develop a direction for a beat, the better, because then you have a rough picture of what you want. I always start blank but develop what I want about a third of the way into things.
personally, i do bass dead last because it has to be an accent to the melody and follow the kick drum.
at the end of the day you should wind up going back and altering bits and pieces to fit much better, fleshing things out.
this is just my thoughts and opinions, i hope they help.