Keep the water quality good the tank clean and make sure there are plenty of pipes, caves etc. Oh yes and the most important thing is to have patience .
I currently have 2 breeding pairs, one pair were together for nearly 18 months before they did anything, they have now had 2 lots of young inside 2 months .
I have found that bristlies tend to do better at temperatures around 75'.
Ok i have been keeping up with the waterchanges and good water, they are fed good diets. My female is looking really fat and full now, but Mr Bristlenose shows no interest and hasn't picked a cave . They are living at opposite ends of the tank. I have taken some pics, which i will post if they will help.