Before you degrease your engine, it’s always essential to prepare it first. You can do that by doing a pre-degreasing cleaning. Open the bonnet and clean the engine with a soft cloth. This will ensure some debris is removed from the engine bay, electric wires etc.
Don’t forget to disconnect the battery and cover all electrical components with a plastic bag, so you don’t short the circuit. If there is an exposed engine air intake, cover that as well with the plastic bag.