The best way to grate truffle is using a Microplane grater. You don't need to buy a fancy truffle slicer. Grating it exposes more surface area of the truffle.
We make our own butter using milk that has been inoculated with kefir (a live culture) - the butter is similar to the cultured butters that you find in Europe. If you wanted to, you could skip making the cultured butter and use about 200 g of the best-quality butter you can find, bring it to room temperature until it's soft, then fold through the truffle - there's no need to add salt if yours is already salted.
I like to keep it really simple and toss the truffle butter through homemade pasta (like this one) - and that's it, so the truffle flavour can really shine through.