Choose paper that can cope with moisture
Thin copy paper can pill or buckle when water-based ink is layered. A heavier smooth sheet gives the marker a better surface and keeps the back of the page cleaner. Test a small swatch first, since different inks behave differently even on the same paper.
Use light, overlapping passes
Fill from one edge to the other without stopping in the center of a region. Overlap the previous stroke gently while it is still damp, then leave the section alone to dry. If you need more depth, add a second thin pass rather than scrubbing the first one.
Keep a blotter under the page
A spare sheet protects the next page and shows you how far the ink travels. Let the finished sheet dry flat before stacking it. The guide to marker bleed-through has more help if the back of the page is becoming a problem.