I usually put on 2 coats of Future, unthinned, to the entire model and let it set up for at least 24 hours before putting on decals. After the decals have completely dried, another 12 to 24 hours, I again put on one more coat of Future, usually only over the decals themselves, and let this dry. Then I apply my washes. After any touch-ups and the washes are dry, it's time for the Dullcoat, or any flat clear coating, to prep the surface for drybrushing and pastel weathering.
Welcome to the forum and hope this helps,
Robert