Pop into Superdrug or Boots and buy a 4 way nail buffer - it should cost £2 -3ish.
Side 1 is like a nail file, so you can shape your nails if they need it.
Side 2 is a smoother. Rub this lightly over the ridges on your nails. It will get rid of them and leave the surface lovely and smooth.
Side 3 is a buffer. Give nails a gentle buff to boost the circulation etc
Side 4 is the fun one. It is the polisher and you use it to give your nails a really good polish. You can get them to polish up so that they almost look as if you have colourless nail varnish on. It's like magic.
You can use the polisher as much and as often as you like.
Something to do whilst watching TV of an evening
You can also get cuticle oil that you apply about once a week (if you remember) and massage into the cuticles. Also just frequent use of handcream will help soften nails up.
Best of luck from Romola, whose NY resolutions were to drink more water and to look after her nails.