I mark, probably a lot more than most. However most of my quilting is full on custom, if I am doing an all over, I usually opt for using a pantograph. For some designs I can get away with just marking the "bones". Like a feather I can just mark the spine and maybe a few registration marks for how far out I want my feather plume to go, this is especially true if I do switch back feathers that curl back on themselves. Almost all of my border motifs depend on symmetry (evenly spaced motifs along the border) so I will definitely mark out my spacing for those before loading. If I need to do a cross hatch that exceeds my throat space, I definitely mark before loading to ensure my cross hatch stays straight throughout the whole quilt. Some stuff I mark as I go and other stuff I do all the marking before loading. If I need to replicate the same motif throughout the quilt, I also mark that either before loading or as I go. I test my marking tools every single time with the exception of plain white chalk as that has always brushed out for me with no issues. But aside from chalk, I test the actual tool I use for marking on the actual fabrics in the quilt. This cannot be stressed enough! I have had tools that worked great on one fabric not come out of another. My friend had a blue water soluble react with a hand dye and leave a ghost mark. My tools of choice for marking are blue water soluble markers specifically made for this purpose. I prefer Leonis brand or Adger brand. Both of these brands last MUCH longer than the Mark-b-gone but I will also use those in a pinch. I have had great success with crayola ultra washable markers but they don't touch anything until I have tested them on the actual fabric in the quilt. If I don't have a scrap, I test in the seam allowance but I almost always have a scrap. For dark fabrics, plain white chalk or white ceramic lead pencil. I have used artist quality chalk pencils as well and have been especially pleased with those. I will use a pounce pad and stencils with the regular pounce chalk, I have never used the ultimate pounce that requires heat or washing to come out. I have used both white and blue regular pounce but I never use the blue full strength, I always dilute it with the white. Again, TEST. I avoid Frixion and all heat erasable pens. I will only use these for marking a seam line, never on a quilt top. Too many horror stories about marks coming back if the quilt is exposed to cold (like in a car trunk travelling some place cold or shipped via air freight). They are also known to leave ghost marks on some fabrics. I won't use them unless whatever mark I make is hidden in the seam allowance.