Form is always the most important thing to focus on in a workout. It protects you from injury and gives you better results faster! As a fitness instructor I often see many struggle to get form correct. Most likely because they learned it wrong in the first place and no one bothered to correct them. They say it takes 1,000 reps to learn something correctly and 3,000 reps to correct! Might as well focus on getting it right the first time :)
Basic Push Ups-
1. Hands just outside shoulders
2. Press out of your shoulders to protect your shoulder joints!
3. Keep chin tucked to protect neck
4. Pelvis should be tucked to help activate core and protect lower back. You are better off having your hips a little higher than below shoulders.
5. Play with range of motion as you begin. If new, don't go as deep or take it to your knees. I will be doing a post shortly on great modifications you can take!