Never tried sharpening them myself, always used a service as standard jobber bits are less than a pound to get done for you. I normally save up a bunch of stuff including saw blades and get them done at once to save on shipping at hit the low volume discounts.

However, its only worth doing on quality components, I wouldn't pay a pound or waste my own time to get a cheap ass drill bit sharpened, I would just replace it.

My saw blades start at like £70 so paying £12 to get it sharpened is good value, but a £30 blade is not really worth it, not least for which it won't cut anywhere near as much material before getting blunt between sharpens. Same logic for drill bills, some of my SDS ones are over £30 each, my augur bits can be over £50 each, so those are worth looking after, not going to bother for a set of 10 bits for £20.