There are a million supplements out there. Here is a good list of the likely natural candidates; http://www.healthline.com/health/herbs-vitamins-supplements-testosterone-levels-balance#UnderstandingHerbsandSupplements7 that said, good general health helps. If you do anything to boost your testosterone I highly recommended quarterly PSA testing. If you are supplementing with actual testosterone it will throw your PSA off some but its important to establish a baseline and watch it for increases. Also check your nuts if you supplement, regularly. If you decide to have a kid, keep in mind that too high a testosterone cuts back on sperm production. Its a balancing act. Good overhealth is key being overweight, diabetic like myself, well it just adds to the issues.
I will be honest I have tried ginseng and Yhombie but didnt see marked differences. I did not mess with many natural supplements since I already had access to actual testosterone.
In the end its going to be an individual journey based on your body chemistry. A bit of trivia, Testosterone is created from Cholesterol.
Also try to stay away from estrogen enhancing foods (soy comes to mind). For more details on that look for Jillian Michaels Master your Metabolism https://www.amazon.com/Master-Your-Metabolism-Naturally-Balancing-ebook/dp/B0024NP59C/ this book has a ton of infor on things the artificially cause estrogen to rise.