Fixing the nails… for those of you who suffer from and splitting nails, here are just a few tips:
I recommend to shorten them occasionally with scissors, it "closes" the edges. And only after than use the nail file.
Another tip for splitting in the nail is to use the "buffer nail file" it really help to stop the split till the nail grows enough and can be cut.
As for the nail file itself, try the crystal nail file. It's just amazing. But not all brands are good, and even in the same brand you can have a really good one and one that doesn't work well (from experience :) ) so you'll have to try a little and find the one that does work. It really worth it, it does wonders compared to the regular metal / paper nail files.
Crystal nail files can be washed with water to keep them clean, and they last for years, so it's a good investment ;)
Pictures for demonstration were taken from the net