When strength training I know the amount of weight at times can be a little scary. You need to get your mind in the right place and be mentally and physically prepared for heavy lifting. If your mind is some where else or you haven't warmed up properly then your form and technique is likely going to be hindered and that leaves a greater chance of injury to occur. Get a good training partner or someone you can really trust to go to the gym with you and motivate you. Have them spot you so mentally you know someone is there to help you if something goes wrong. If you've mastered the exercise and want to break a PR (personal record) then I suggest to warm the muscle well with lighter sets to activate all the muscle fibers and to fill the muscle with nutrient rich blood to protect the muscle. Think all your action into the muscle, lift with full power, and that's where all your power will go. So dont be afraid of the weight. Just be sure you are mentally and physically prepared! You've had your eyes on that heavy a** set of dumbbells on the rack for a while now so suck it up and show it who's boss! The main thing is to believe in yourself and don't be afraid to fail. Eat well and hydrate well!