Whenever you are filing your natural nail, use a crystal file (bottom left) for free edge. Emory board files (bottom right) have been known to cause more splitting and is rougher on the nail.
I recommend using an orange wood stick for a cuticle pusher as it is softer on your nail beds versus using the metal ones. Make sure your cuticle is soft before pushing them back.
It is best to refrain from clipping your own cuticles, as it can cause damage and/or infections.
A block file has multiple sides and grits to be able to tackle any situation with your nail plate. When looking to purchase a block file, look for one with a finer grit to make sure you don't damage your nails as you most likely haven't had proper education on how to correctly file. A recommended block file is one with an orange sponge center (as shown below). They form to your nail instead of fighting against the natural shape, allowing for a more gentle file while removing surface shine.
Alcohol wipes are a necessity when properly taking care of your nails. They clean the plate and will allow for the best surface for a strong adhesive. An alcohol wipe on a lint free 100% cotton pad/ball is recommended. This is for polish removal on natural nails. Make sure you are using 100% cotton or you will end up with polish everywhere as it is does not absorb well.
Before applying nail polish, always prep the nail by filing free edge, softening the cuticle with cream/oil, and pushing back cuticles. Do not use a heavy grit or file too aggressively. The goal here is to make the surface of nail plate non shiny. This allows for a better grab of the polish. Cleanse the nail of dust and oils with alcohol wipes. This allows for a better grab of the polish. Cleanse the nail of dust and oils with lint free alcohol wipes.