I am a man. I need long fingernails for the job I have- just thumb and pointer finger. It is fiddly manual work- they provide tools but often my hands aren't good enough to use those tools effectively. I also do some private tutoring and I need for my fingernails not to look dirty. How can I achieve that look- hopefully cheaply?

I am a man. I need long fingernails for the job I have- just thumb and pointer finger. It is fiddly manual work- they provide tools but often my hands aren't good enough to use those tools effectively. I also do some private tutoring and I need for my fingernails not to look dirty. How can I achieve that look- hopefully cheaply? The tips develop an off-white somewhat yellow look and grey at the corner.