Though I'm not a huge fan of Wipe-on Poly by Minwax, it may be worth trying. Very easy to work with, especially on fret work. Use a sponge brush to apply it liberally, work it into the wood with a rag, let it set for a few hours, do a light sanding and repeat the process. Boom, it's done
If I'm doing a project in pine or Baltic birch plywood, I use spray shellac. If I'm making something out of walnut, alder, maple, etc, I use Danish oil. Yes, it takes longer. A LOT longer. But that's okay, because to me, after applying a coat of Danish, letting it sit a few days and again repeating the process a few times, I end up with a piece that has a very deep and rich luster.