One thing to add to what CGR said.....

Once you've flown the plane and gotten trimmed out in the air, take another look at the position of your trim settings. The goal should be to have the plane trimmed to fly straight and level with the trim settings essentially at their neutral position, or a click or two one way or the other. If you've got one that is more than just a few clicks off of center, it's desirable to re-adjust that surface with the linkage.

What I do is use some sort of marker to indicate the neutral trimmed position of the surface in question, center the trim and then adjust the clevis at either the servo arm or the control horn to put the surface BACK at that position, with the trim centered. I'm not obsessive/compulsive about it, but I don't like to have a control surface trimmed for neutral flight, and have the trim setting halfway between neutral and maxed out. My goal is usually to have the plane properly trimmed, and all the trim settings no further than 5 clicks from center.