Hello Mike,
there are many trim guides on the net, as the one that has been suggested. IMHO it is important to point out that trimming is a process, i.e. there are several steps to perform in a particular order, since many variables interact with each other.

For example, your problem could be due to CG (pitch with rudder I mean), which is the first thing to check, as the experts suggest. Moving it forward will reduce the need to a mix, but the best thing is to follow the trim guide from the beginning to the end. The most subtle settings are CG, incidence and thrust angles, since they all play together. Then you might want to think about mixes, but not before!

Hope this helps!