That said, you need to first find the problem that is causing the blades to lose their sharpness. Most likely, the blades have not been oiled, have sat and corroded, or they have been used to "clip" something besides hair. Clippers are usually designed so that they can be taken apart for small repairs and maintenance - there should be one or two screws holding the stationary blade in place. Remove these screws and disassemble the cutting head, remembering the order and placing of each part.
First, clean all the loose parts by filling a small dish with 90% isopropyl alcohol (the more expensive one in the alcohol/first aid section) and soaking the parts in that. Rub them briskly with a soft cloth to remove any dirt, corrosion, or old grease. Check between the blade teeth that they are not clogged with any debris. If you feel the need to sharpen the blades at this point, do so by placing the blade flat on a fine-grade sharpening stone (with a drop of oil) and gently but briskly, keeping the blade flat, grind it in one direction. Do this about 5-10 sweeps. Then, repeat in the other direction (do not go back and forth - always sharpen one edge at a time!)
After this, take the two pieces of blade, inspect them to make sure they are "cleanly" sharpened, and wipe them again with the alcohol. After making sure that all the innards are completely clean, re-assemble the cutting head. Make sure that the blades are straight and centered - this is very important! - and at the correct displacement at the end (usually only a matter of a centimeter or so - two much space and there isn't enough surface-against-surface to cut all the hair, which might have been the problem in the first place.) After getting the blades properly aligned and staight, tighten the head screws as tight as you can.
Place about three drops of a light=grade oilon the blades - 3-in-one oil works, and hydraulic jack oil is great too. Plug them in, let them run together for a while to get lubricated and to de-burr themselves, and test them on some hair. Hopefully they will work now!
Ok, if they don't, then you most likely need to do one of three options, depending on how much you paid for the clippers. If they are a good brand (like Oster) and were pricey, you should be able to go to any beauty supply store and either buy or order a new blade set. Keep in mind that blades can be pricey - but if it's a reliable clipper brand, a new blade is a good investment.
Another option is to have the blades professionally sharpened. Check around for a blade-sharpening service - sometiems they are non-local and you have to ship the blades to them. But tif it's an expensive set of clippers, sharpening may be a good, economical option.
If the clippers are NOT a good brand, or were cheap when bought, or seem to be low quality, you are probably best to just buy a new set. Most major department stores carry a variety of clippers - spend your money wisely on a dependable, simple set of clippers. Do not go for the lesser brand's expensive clippers with lots of "functions" unless you are positive about the quality. In the long run, a very simple set of clippers is probably better- cutting, and longer lasting, than a comparable-priced set with lots of do-dads. Also remember to buy clipper oil!
And with the new clippers, follow the manjfacturers instructions, keep them clean and oiled, and you should have a good set of clippers to last a long time.
Contrary to some beliefs, electric shavers can become dull. You can of course purchase a new one, purchase replacement heads, or you can use graphite powder that you sprinkle on the blades and spin for a few minutes.
You can usually find graphite powder in most hardware stores.
If you paid a lot of money for the scissors, which I'm assuming you did, DO NOT attempt to sharpen them with anything on your own, let alone a stone. I know it's tedious, but paying to have your scissors professionally sharpened is the only way to guarantee that they last a long time. However, if you're talking about a cheap-o pair of scissors from a drugstore, check YouTube.
Just with a regular pencil sharpener
There are a few benefits of using a double-edge or "safety" razor blade. One benefit would be the fact that it is harder to cut oneself with the blade.
A double edge razor is one where both sides of the razor have a single exposed blade, with no guard or moisturizing strip. Double edge razors can be purchased from a variety of retailers, including local drug stores, and online retailers such as Amazon.
Glass window use a single edge razor blade.
You've got to shave it off with a single edge razor blade
-I use a razor blade or the edge of a craft knife blade, VERY carefully.
a bleeding hand clutching a double edge razor
Forward, as if you were whittling. Drawn the other way the blade develops a "wire edge"- a cutting edge that will dull as soon as it is used.
A lawn mower blade can be sharpened with a blade sharpner. Any major hardware store can do this for you. You remove the blade and clamp it to a flat surface. Then you use an angle grinder to sharpen the edge using the original angle as best you can. Safety glasses are always necessary as this is dangerous to your eyes.
Lancet
the edge of a razor blade, but impossible to snap back on with out their tool.
The Razor's Edge was created in 1944.
A 'filo' is a sharpened edge, like that of a blade. 'Dos filos' means 'two edges.' In Spanish, it's 'one filo' and 'two filos.' 'De dos filos' means double-edged, like a sword or a razor blade.