When all your frets are in place, they'll have to be finished. The cleaner your fretwork is, the more you will enjoy playing your instrument.
Start by cutting off excess frets. They can be sharp and make your fretboard less manageable.
A fret cutter has a flattened head with which you can cut your frets close to the fretboard. When cutting, try to keep the pressure leveled and in any case do not pull upwards. You do not want your frets to be pulled out.
After cutting, pieces still stick out. Personally, I find the best way to remove them is with a flat fret level file. You can also use a special edge file and even sandpaper around a block can also work. File or sand till the sides are smooth and no frets stick out. During this you can also file the corners of your frets in around a 30 degrees angle inwards so that they do not get in the way while playing.
Due to the pressure that is applied during the fretting, it is possible that not all frets have the same height. As a result, a string can start ringing on a fret, your tone can get deafened, or the intonation may deviate on a fret. So, it is essential to get everything on one level. If your fretboard is already glued to your neck, you will first have to straighten the neck. Keep your neck at eye level so that you can look over it with one eye. This way you can see if the neck is straight. If it is not, you can adjust the radius with an Allen key until the neck is straight.
Frets leveling can be done with a fret level file. Make sure you follow the line of the fretboard and the radius. What works well for me is to do this with the radius block and 120 to 180 grit sandpaper. This way you ensure that the top of your frets follow the radius of your fretboard. Work calmly, as it can go quite fast. To follow your progress, mark each fret over the entire length with a felt-tip pen. Use a fretboard protector to avoid any spils from ruining your fretboard. With this line you can see if all frets are hit by your file or your radius block. File and/or sand several times and then set new stripes and check again. If the top of the felt tip is removed on every fret after 1 sanding movement, then you are okay.
After leveling, the tops of your frets have flattened. Then they make too much contact with the string and they do not play smoothly. So you have to make them round again. Use a fret crown file or a fret dressing file. Draw a line again with a felt-tip pen over the top of your fret and pull the fret file over in smooth motions. You can put light pressure, but do not put too much pressure, otherwise you will damage your frets and you will have a lot more polishing to do. File until almost all felt pen has disappeared and you only have a thin line on top. Also round of the angled edges of the frets for more comfort. Repeat for all the frets.
After crowning and dressing there will be some scratches on your frets, scraps of felt pen and they might be a bit matt. Time to polish! Protect your fretboard with a fretboard protector or with masking tape. Take 0000 steel wool and make a small knot that you can hold between your fingertips and with which you can put pressure. You can also use the fret polishing gums for this and they are very handy to do a touch up of your frets after a while of playing. Brush fret for fret until you are satisfied!