Protect the surface first
Alcohol ink travels through ordinary copy paper quickly. Put scrap paper or a bleed-through board beneath the page, and choose smooth paper made for markers when possible. Test the printed outlines too; some printer inks soften when they meet a wet marker. Our guide to marker bleed-through compares the common paper problems.
Layer from light to dark
Swatch the colors together before touching the page. Fill the lightest base color while it is still workable, then add a darker shade along the edge that should recede. Keep the marker moving and overlap each stroke slightly to reduce hard bands.
Save the small details for last
Let large regions dry before adding shadows, highlights, or a fine outline. Alcohol markers can re-wet earlier layers, so a light touch prevents muddy corners. A simple page from the free library makes a useful first test.