I recently found a glue roller bottle at at woodworking supply store.  It applies just the right amount of glue and the clean up is quick and easy.  You just remove the roller top to wash it, and replace it with the smaller cap.  I fill the roller bottle from the gallon jug of Lineco Archival glue that I have been using.

 

First roll the glue onto your board.  I use a 1/4 inch birch plywood with an MDF core.

 

Next, place the glue side onto the precut piece of linen.

Use a roller to adhere the linen to your board.

And trim off the excess.  I don’t find that I need to press the boards as they dry.  They don’t warp, and if they are rolled well, the linen stays down tightly.