Fingernails and their care
Right hand technique (or left hand technique if you are left-handed) is where the drving force behind flamenco is and the fingernails are going to be very important in creating the sound.
The nails create the impact that allows the strings to vibrate and produce a clear note, so they need to be long enough to connect with the string but not so long that they will get in the way of movement from one string to another.
As a general rule, the longer the nails, the easier and the more powerful your rasgueados will be; the shorter the nails, the easier tirando, picado and arpeggios will be. There is a compromise here: longer nails may be needed if you accompany dancers (a lot of rasgueados are involved in accompaniement) but they may be a hindrance for playing solo pieces.
The nails also need to be strong and correctly shaped.
I have added the following videos to help with this important aspect of flamenco, everyone has different needs so you may have to take the information that you think best suits you and try out various ideas before you find the one that is best for you.