I have some MDF doors in the eaves cupboards, just plain 1.5 cm MDF. There
is quite a lot of pine in the room, and I have varnished that. It looks
great. I tried varnishing the MDF doors, and it looks pretty awful, just a
plain kahki colour, and the finish is not good, with the varnish sinking
into the MDF. (I have just finished the second coat and it looks the same. I
guess that if I keep going I will eventually get a decent finish, but it's
only MDF after all.)

I tried a mahogany varnish on a bit of scrap, but the result is even worse,
just a sort of mucky brown.

I could paint the doors gloss white, which would go with the walls, which
are white emulsion. Any suggestions before I do that?

By the way, I have varnished the room side of the doors. Do I have to do the
same to the inside to stop them warping?