Robert asked me for a more detailed explaination, I'll try to describe it as good as I can.
Lets assume you have a 1.25" blade with the ji roughly profiled in on the shinogi/mune and the ha (I don't cut the mune until the very last - just the shinogi at this stage).When these surfaces are about 80% filed in it is time to start the kissaki.First,shape the kissaki profile (just the end profile,not the kissaki-ji).At this point you have two bevels going straight down the blade above and below the shinogi,and ending at a blunt curved tip.Approximately 75% below and 25% above the shinogi.The shinogi-ji and mune-ji make up the top 25% and the ha-ji is the bottom 75%.We are only concerned with the ha-ji right now.
The kissaki-ji will make a 145-150 degree angle with the ha-ji (for the purpose of this example),and is slightly curved (lets assume it is a chu kissaki ,or medium point).File from the mune perpendicular to the kissaki (not perpendicular to the ha) and shape the bevel,using smooth strokes that go from saki (point) to yokote.By keeping the file cut downward and perpendicular to the edge you will make a sharp line as you intersect the ha-ji.The trick is to keep the file flat,don't go around at the yokote like you would if filing the tip of a bowie knife (imagine you are using a 2" wide file,and making one straight cut).If you are making a powerful kissaki with extra thickness,and a convex ji,file it that way,or you can make it flatter, like the ha-ji, for a thinner and sharper kissaki.Either way the yokote will still be a sharp line.
Once the kissaki is established (and the yokote is defined) you will have to alternate from a stroke down the ha-ji to a stroke on the kissaki-ji,back and forth,etc.Turn the blade over often and do a little on one side then a little on the other. When the kissaki and ha are getting well along the way start adding the shinogi and mune to the series of cuts. At this point the shinogi will have moved up towards the mune a good bit.Don't worry it will come back down and be established as you bring the shinogi-ji along.
Once the blade is 90% shaped it is time to go to stones or a HARD sanding block and GOOD grade paper (I'll describe paper).As in filing,all strokes should be smooth,long ,and in one direction only (usually from machi to saki) .Start at 120 and do EXACTLY as you did with the file.go to 220 and then 400.Change the paper often, fresh paper cuts better.When the blade looks exactly like you want it to,and is about 95% done,do the HT,creating the sori and hamon.
Go back to the 220 paper,400,right on up to 8000 if you like. Finish with a hard leather strop block make by taking a 2X2X8" wide block of very hard wood and surfacing the bottom with hard leather.Charge the strop with green chrome polish,rouge,ZAM,or whatever final polish you like.I rout deep grooves in the side for a good grip and to keep fingers away from the EXTREMELY sharp edge you are polishing.Use smooth ,slow, firm strokes to polish the edge (and make the hamon pop).Recharge the strop very often.
A proper sword jig is a good idea to do all this filing ,sanding,and polishing safely.It is somewhat like a sawhorse with the top padded with leather and a clamping method to hold the blade firmly down.
Be aware that polishing a katana is very dangerous if absolute attention is not applied (and fairly dangerous when you are paying attention!).
I hope this helps a little.There is,of course a lot more to it than this,but this will give you the basics.
Stacy