If it's been more than about 2 weeks since I last long-armed, I always have to practice up first. It's a physical activity that requires muscle memory.
Like Zozee I have some random sandwiches that I practice up on. Then maybe I'll even do a quick little easy baby quilt or other simple project. Then I load on the queen sized/more difficult project.
Just to make sure everything is still correct from the practice piece, I usually pin on a scrap of fabric to outside the edge of my project and run through a few stitches with the actual batting and backing I'll be using just in case I need to make any other adjustments.
I find I have to constantly keep on myself about consistency and really have to do everything of a stage during that one stage, especially on things like freehand meandering and stippling so that the relative sizes stay consistent from top to bottom.
When I get on a roll of quilting down though, yes -- they keep getting better and better until my body is worn out and then another couple of months past and then I start the cycle over again.