Angled drills allow you to make precise drill holes in limited / awkward spaces through most materials (with the correct drill bits).
If using an Angled Drill it is usually because of limited access, so the use of protective goggles or safety glasses will be required especially if working above your self.
Angled Drills come in mains and battery powered form, the latter giving you more scope for accessing more limited work areas. Also chuck and keyless chuck options depending on which model you feel more confident with.
When drilling through timber with larger wood bits the drill will sometimes jump or catch when starting, you would be advised to buy a model with variable speed control at the trigger. Stop / starting in limited spaces can be awkward and dangerous.
If your choice of Angled Drill is a battery powered version it would be advisable to purchase a model with a good strong power life (18v) recommended, this makes drilling more capable through all types of material and again gives you a longer working period in confined spaces. You do not want your battery to go flat.
Some of the more costly models have an 180° turning drill head which makes for a more versatile Angled Drill. As with any power tool one golden rule which should always be followed is ‘never force a power tool’as cutting and drilling becomes hard to control.
When using a Angled Drill (as with any power tool) always make sure you are using new or drill bits of good quality. This makes the work load on your Angled Drill much less and stops you trying to push the power tool which also cuts out possible accidents and wear on the motor of your drill.