I'm using FMQ for about the 3rd time on a larger lap quilt. I have done several placemats this way, also, but that's about the extent of it. I'm using an open-toed darning foot for this. Here are some things I have learned:
1. spray baste your quilt. I thought this was just for baby quilts and other smaller projects, but the can says "will baste about 3 queen-sized quilts" so the manufacturer had bigger ideas than I had!
2. instead of thinking of the large quilt divide your project into managable pieces. I do this by sewing quilting lines both across and down. My current project is 6 blocks across by 8 blocks down so I did a scallop stitch across 3 times - every two blocks - and down 2 times - also every two blocks. I now have twelve 2X2 block sections to work in - about a 16" square in this case. This stabilizes the quilt - it's not going to shift on me - and provides me with smaller sections to work in. On another quilt I straight stitched 1/4" on each side of the seams to make smaller sections. You could call this "utility quilting". I actually like the look of it as well - especially from the back.
3. Starting with the outer blocks I put my needle down in a corner of the section to be quilting. The edges of the sandwich tend to come lose as I work with it so starting with the outer blocks prevents it from coming apart on the sides. My machine has a whopping 4 1/2" work space to the right of the needle so I'm really stuffing the quilt through there. Since I've done the utility quilting in step #2 above it's not going to shift on me.
4. Pull both threads to the top of the quilt - preventing any bird's nests from occuring on the back. (holding your upper thread, put the needle down, then pull it back up. The bobbin thread will come up with the upper thread - pull them both to the top then tuck them to the back of your foot.
5. Move the quilt slowly under the needle. If you move too fast the stitches will be large. I have gloves to help grip the quilt, but so far prefer my bare hands. This also means I do one section then come on here and play - my hands, shoulders, etc get tired!
6. Imagine - or even draw with removable pen/pencil/chalk - a snake outline. That's not my idea. Got it here:
Paths to Better Stippling/Meandering
Using this prevents you from quilting yourself into a corner. Other images that have been suggested on here - a cactus shape, sea weed shapes, puzzle pieces...
7. Repeat until done!
I have found in my years of school teaching that it's not the advanced students who do best teaching the less-knowledgeable. It's the kids just a bubble ahead of the other learners who do the best so ... those of you a bubble ahead - please add your advice!