Trim nails little and often, do not let them grow too long or they damage the root by leverage pressure from the shoes.
Trim the nails straight across and do not cut down the sides as this often leads to problems.
Nail conditions rarely if ever resolve spontaneously so seek attention early rather than later.
If you have to use nail varnish make sure you use acetate free varnish remover.
Keep your feet clean but do not over wash the feet as skin is usually capable of looking after itself with minimal intervention. Too much soap can dry the skin out, stripping away the bodies natural oils.
What can I say about this that will be realistic. Make sure your footwear is as comfortable as possible. Be wary of loose slippers, the backless slip on types, as these allow your feet to slide forward and can make your nails sore or even cause corns and calluses.