Get in a group
Playing with other people is one of the fastest ways to get better at your instrument. You probably realized this as soon as you started playing in your first bands. Once you've had a little time to develop your secondary instrument, the first thing you should do is try to get involved with a group.
It can be a little nerve-wracking to try to join up with a band when you aren't fully developed on your new instrument, but if you find a supportive group of players, it's a lot of fun. You might even be able to rope some of your friends into it! Try to organize a weekly jam where nobody is allowed to play their primary instrument! I've done this in the past, and it's a total blast, and it helps everybody improve on whatever secondary instruments they are working on.
Alternatively, try looking at some of the local music schools in your area. Oftentimes, in addition to lessons, they'll offer "band"-type performance programs that you can get involved in. These aren't free, of course, but they'll offer you a safe and supportive environment in which you can grow and play with other musicians.
(Resource from the web)