If you google about the subject, you will find numerous photos about pumping. Some will impress, some will disgust, as there are guys out there who, in their quest for size, end up distorting and basically mutilating their penis into an unrecognizable bloated and scary-looking organ. Surgery doesn't always work, and their are risktakers out there who inject saline solutions. Dunno about you, but that scares the shit outta me !
Keys to success : LOW pressure, over extended periods with frequent breaks (remove the tube and massage).
Cock rings : you don''t want to end up in Emerg at the local hospital, when you can't get the damn thing off. There's only one option, and it involves a small electric surgical saw. Nuff said.
STRONGLY suggest you start with a leather strap with clasps that can be removed instantly. Using rubber, elastic, silicone and/or rigid (metal) cock rings can totally cut off blood flow to the cock. Very bad and can cause permanent (unrepairable) damage.
You want the cockring to restrict blood flow to the cock, not block the circulation. Also suggest you get a cockring that fits around the base of your cock and balls, not just your cock. Again, the cockring tightness is critical here, which is why they often come with a warning to wear them for only twenty minutes, max. Oh, and if you get drunk and fall asleep with it on ... disasterous, to say the least.
These toys can be a lot of fun. Just be careful, we are talking about damaging not just an organ, but your manhood here.
Take care.
BTW, your shot of your bulge in the Cin2 underwear is hot. I assume these are the ones with the internal strap that pulls your manhood up and out a bit. Very HOT !