If your having a hard time with openers one little 'cheat' that helped me was we'd take girls to the bars with us. Wether these girls were friends girlfriends or friends it didnt matter.
We would then get proximety and the sets would open on practically anything we said. Alot of your confidence is based on your success rate, so if opinion openers failed the first few times your going to always open the set sounding as if you don't really need an opinion.
Also, I agree with you, opinion openers are a bit unatural and almost beta to say ' I want your opinion'. I really like mixed sets as well, you can just talk to the guys naturally, throw in the 'so how do you all know eachother?' then move onto the target where no opening is neccesary.
Practice makes perfect
