Tools needed: 

• A 3mm hex key (I may pick up one of these.)
• A 2mm hex key 
• A screwdriver that fits your pickup height adjustment screws

Your pickups should not be too close to your strings, nor should they be too far away. Check with your manufacturer, but a good starting point is for the bass side to be 3mm away and 2mm away on the treble side. 

To measure this, hold down the E string on the last fret. Then run the 3mm hex key between the string and the pickup. It should just fit. Adjust the pickup height as needed until it is right. Do the same on the treble end (G string) and use the 2mm key this time. Adjust as needed.