Really good overview of the system. Watch the vids
If you want to better understand how conversions take place in more detail, wiki is your friend.
Some decent suggestions on script free optimization
In general, if you want to try and optimize naturally first you might try some research on the following:
Omega 6/3 fats
Magnesium - transdermal jacked my DHEA up.
Depending on symptoms, you could also take a peek at your thyroid when/if you have a solid supplementation program for general health and your diet is reasonable. Is TSH higher than 2? How are T4 levels? How is the conversion of T4 to T3?
After that you might want to take a cheap E2 test. If it's much outside the 20s, look at options to reduce it.
You could then look at SHBG levels. If they are high, look at options to reduce.
If you are feeling and/or testing better, you could try natural boosters. This is actually a lot harder to sort through that HRT. A ton of shit products and shit information on natural test boosters. I had good luck (blood test verified) with AlphaMale but plenty of people claim Trib does nothing. I feel like DAA has worked for me, but don't have solid blood work to prove it yet. DAA is a pretty cheap option if it works for you. After that there are 1000s of different compounds/herbs some will swear by and 10s of 1000s of combinations of those compounds/herbs someone will try and sell you on. I would stay away from anything you can't find blood work comparisons on.
After all this I might end up needing HRT after all, but going through the process has been educational. maybe a little expensive with out of pocket testing, but educational.