a coloured grain filler to pop the timber usually works well.
I've heard of , wait for it, egg whites being used quite effectively for grain filler...
Or use a coloured stain to pop the grain, sand it off and just go from there. Whilst there are plenty of advocates against thick finishes, a thick clear on top of stain will alleviate the need for grain filling.
Or practice on scraps with a local products as a grain filler and see what the test results yield, you might find the next new thing