It is important to use maximum pressure when smoothing out the veneer by hand. Don't use a “J-roller” as with Formica to smooth out flexible veneer, but rather a scrap piece of wood approximately 14" long and 5" wide for your veneer scraper.
Lightly sand the edge to take the sharpness away and create a slight radius - the smaller the radius the better as it will produce the greatest pressure. (A 1/16" radius will produce 4 times more pressure than a 1/4" radius.) Hold the scraper in both hands and use it like a squeegee to smooth out the veneer from the center outward to the edges. A warm iron may be used to help reactivate the cement and put “bubbles” down tight if there is enough cement to re-contact the veneer. If cement is too thin, the bubble will pop back up.
When you put the iron on the veneer, be sure to use a piece of grocery bag paper under it to keep the veneer face clean. Keep the iron moving and never keep it in one place or you might soften the factory adhesive and cause the veneering to loosen. If veneer should come loose under heat, then reheat and scrape hard until the area cools down again.
Coat both surfaces with adhesive, just like Formica. Make certain to read up on the glue manufacturer's instructions on workability.