Regarding nails:

First of all, I use acrylic on my nails. I go to a saloon where they put that on, and then I shape the nails myself. The thicker the layer of acrylic is, the better the tone is, in my opinion. In the pictures below, you'll notice that it's been awhile since I put on new acrylic (I should do that today! :) ), maybe a month or more, and the acrylic only covers half of the nails now..

This is the shape that I use on my nails:

For me, it's important to file the nails in this angle (below). When I play a lot, the strings automatically "file" down the nails in this shape, so I try to get the shape of the nails already in that shape before, so that it feels natural right away. I want a smooth angle (with no sharp edges), and If I hold the nail file like this, it's easy to shape it in a good way that works great for me.

Hope this helps, and let me know if you have any further questions! :)
Kind regards /Emil