Theory: Better health/circulation = better erection. Stretching the penis over time = new cells/tissue = larger penis. Better nutrients = better sperm. For better erections (might make it a little girthier/longer because better blood flow, will definitely make it look bigger if you're overweight - technically size stays the same but if your dick is harder with better blood flow, it will feel girthier and look bigger (but it's really not)). For mental health: 1. If someone you're having sex with isn't happy with the size, it's their loss, move on. Find someone who is. They exist. Stuff you can do without gear: 1. Lose weight. Cut and bump up your cardio. 2. Eat better. Drink more water. 3. Up your Zinc. Helps with cum, too. 4. Up your fish oil. 5. Up your vitamin D. 6. If you smoke, STOP smoking - smoke = bad for blood, cell growth. 7. If you drink, cut back. A little won't hurt but empty calories aren't good for you. 8. Up your collagen (do this anyway, it's good for joints and your skin). 9. Find natural ways to boost testosterone (strength training helps a lot, so does regular GOOD sleep and Zinc too). Bonus: Kegel exercises. Stuff you can do with gear (works best if you do all the stuff above, especially weight loss, cardio, and upping collagen): 1. Get a penis traction device. 2. Use penis traction device 4 - 8 hours a day every day, take one day off (8 hours is best, but 4 is minimum - the less you use it, the long it will take to do this). 3. Get a pump. DO NOT PUMP EVERYDAY. Pump once a week or twice a week. Best to do it after your 8hr routine with the traction device. Traction for 8hrs, 1 hour break, pump for 5 - 10 minutes. 4. Repeat steps 1 - 3. Measure yourself. 5. TAKE A DAY OFF, maybe two. Give your dick time to heal. Expect, at worst, have a way better erection. Lower end results WITH ONLY TRACTION, expect to gain under an inch in length (erect) and half an inch in girth (erect). Pumps are hard on your dick, so use sparingly and don't do it for long. High-end results are an inch and a half+ in length (erect) and over an inch in girth (erect). There you go. Not medical or cock advice.