I'm right in Lena's camp. It takes a bit maybe to get the idea of the meanders and how to not get yourself in a place you can't get out again -- but even if you do, is it really that big of a deal?? For me I find music helps keep my rhythm and keeping my size consistent.
From a practical standpoint, if I'm going to mark, I prefer to do so before sandwiching, I can get a better drawing on small bits of surface with a hard surface than I can with the batting and backing included. If I'm using pounce pads the stencils go on pretty nicely on the sandwich, but can wear off so you have to decide on how to deal with that. But, I also have to deal with vision issues. I've never found the best marking techniques for my typical scrappy style, using lots of small pieces of light and dark or different colors.
So I've also used paper, typically I use parchment paper I get from the dollar store, comes in 1 x 25 foot rolls. The supplier has changed in the last couple of years and/or my move to a different part of the country and I seem to have a bit more issues with the current stuff, but it is pretty darn easy to work with and a nice price. I would buy pantographs and copy them onto the parchment so I could sew through. Yes, time consuming, but that is what it takes for me to get the results I wanted. If you use white thread there is a chance that pencil graphite or sometimes ink can carry through onto the thread and be almost impossible to get out again, would not recommend the pencil/parchment combo on a white on white type project.
Some of the ladies in my sewing group are doing very well with pre-printed designs as well. In general they do not have much experience in machine quilting.
I found in terms of improving my skills I would do a rather basic grid of some technique in the bed/center of the quilt and a more complicated design on the border, If you have a serpentine stitch option on your machine, I really like that for a number of reasons for the grid.
I've tried the using the design on the back and that hasn't worked too well for me, mostly tension issues being more noticeable on the top. But if your stitches are nice and consistent from both sides -- hooray for you! I do recommend a really good sandwich and would probably use spray baste... A lot of stitching tension issues disappear with the first wash but some don't so much, especially small tight arcs for me, I get the eyelash thing.