While I know how to operate a power drill in general (by the manual, so to say), I am wondering which things I should avoid of doing to it, in order to get the best out of the drill. I want to know about things that I might use a power drill for, because it seems like a genious idea, but which put the mechanics and electronics at danger. As an example: I see and am tempted to tilt the drill in a hole or apply perpendicular force on the drill bit as in milling. While I think this is a common idea and practice, I am not sure about how much damage this does to the drive, if at all.
Some other helpful hints (not from Heloise)
0) ALWAYS wear
gloves and eye protection. (Note: if you're using one hand to hold down the material being drilled, a glove can reduce injury if the drill bit jams. On the other hand, you should never depend on body parts to hold things in place)
1) When drilling into soft material such as plastic or pine, withdraw the bit periodically to clear out shavings.
2) When drilling into metal or hard materials, use a center punch to give you a starting hole. This avoids "wander" when you start up, and reduces the need to push down hard in an attempt to avoid "wander."
3) Don't put a gigantic size bit (e.g. spade or Forstner types) in a drill not designed for one. The torque required will burn out the motor.
4) Not bad for the drill, but bad for the bits: when using really small diameter bits, be careful and gentle or they'll snap. If you've got a 3-prong chuck, make sure the drill bit is properly centered before attempting to drill.
Note: it's fine to drill at an angle so long as the applied force is along the shaft of the drill bit.
Just some things I see on jobs all the time:
Do not use a power drill (you want to keep mix things). You will blow out the motor in a good power drill by using it as a mixer. I see my guys use their Makitas with a mixing rod. And have seen many ruin them. I simply give them a 30 year old craftsman electric drill I have that I would give away for $5. It over heats after 5 mins but gets the job done. They also make specialty drills for mixing.
Your drill doesn't always (or hardly ever) needs to be set at the highest torque setting. When drilling it should be controlled. Doing it too fast, too much torque, will just give you a lot of stripped screws.
Buy good bits, whether this is actually drilling bits or bits used for screwing. It is such a low cost way to not only make your life easier but also make your drill last longer because it isn't being strained for no reason. This includes the right tips for drilling through wood, metal, plastics/others. This includes have a wide variety of bits that sink into your screws perfectly. If you use a slightly small bit on 2000 drywall screws you will spend a lot more time, drill will work harder, and you will strip some screws.
Pre-drill where needed. When wood screws are sinking into dense wood the excess scraps need a place to go. Not predrilling puts a TON of strain on drill and often will require multiple tries.
Countersink where needed. There are certain situations where countersinking save a ton of time and strain on drill. Using concrete board is a perfect example. Most concrete screws won't sink right on first try - maybe 30% if you are good. Simple dimple with a 3/8" bit save you time.
There is an art to drilling. Yes it is easy to screw in a drywall screw but there are 100s of uses for a drill and most are a lot harder. You holding the drill straight make a huge difference. Being off by 10 degrees makes a big difference - doing that consistently can make your life a nightmare on big jobs. The second part is putting good leverage (push) on the drill for harder screws. The drill should move the screw/bit around - you should be pushing it in (or drill works a lot harder).
Don't use a regular drill for masonry work that a hammer drill is for. Not only will this take you forever, but most of the time it simply won't work, ruin your drill, and your bit.
Take care of your drill. Keep it clean. I see guys leave thinset/mud/drywall mud on drills and they will wonder why rust appears or there are electrical issue...
Corded drills provide more power. I love my cordless and it's my #1 used tool but there are things it isn't mean for. When I need a ton of power I use a cheap corded drill. It works better and keeps cordless working longer.
a drill bit is not designed to cut on the flute like an end mill. However you will see many folks making a hole larger by moving the drill off axis. It works but not clean. The biggest advice I Could give is to use cutting oil and slower speeds when cutting metal the goal would be to have a long chip develop this shows your speed and pressure are correct for the material being cut and the bit will last longer.
If you put a hole saw onto your drill, avoid going fast and always brace it well in case it catches. I have a bad wrist to show for careless hole saw use.
If you're drilling metal, use an appropriate type of bit (HSS, whatever), use some cutting lube, and drill for short periods with breaks between. Don't run the drill too fast either. If the bit overheats you'll ruin the temper and destroy the bit. Since the title of this question really should be "tell us the dumb ways you broke stuff", I'll mention that I've ruined HSS bits in maple too by drilling to fast for too long until they overheated.
If you're using a drill to drive screws, most particularly those furshlugginer phillips monstrosities, use an appropriate setting on the torque clutch to prevent camming the bit out of the fastener head and damaging both the screw and the bit. Also use the torque thingy to prevent driving screws too hard into wood, sheetrock, or whatever.
The back of the drill looks like the poll of a hatchet, but it's not a striking tool. I know, I know, why do they make it LOOK like one if it's so ridiculously fragile?! Craziness! But I learned this the hard way: You can't drive a nail with it. More subtly, you can't hammer in a screw with it either.
Drill pilot holes and gradually widen them. This saves you energy and reduces wear on your drill bits.
Always use the supplied handle to brace the drill. This keeps you from injuring your wrist if the bit catches.
All these answers are along the lines of "do these things" but the list of things to not do with a drill is infinite and includes things like "don't drill into yourself or other people" and "avoid setting yourself on fire while drilling".