Over the years I have learned a few things to make a guy feel more comfortable about.
1 - If the pt is not in a crisis, tell them you would like to do a 12 lead, explain it to them and ask if it would be ok. ( all male crews in my house )
2 - Using the back of your hand to roll the boob works great.
3 - You can place the patches without exposing the boob ( at least nippleage ). Work above and below the bra/shirt. This is great for shopping center calls, etc... anywhere that privacy is tough.
4 - You can have them hold it up to get underneath as well ( works well with the younger female crowd
5 - V4-6 go under the boob, just under the fold at the crease. I lift the boob 1 time and place the leads all at once. Not cool to lift it 3 times ( at least professionally )
6 - V3 does not go over the nipply.
7 - Use your imagination and imagine that the boob in invisible to line up your leads appropriately. You may be off a bit... but ya know... in the field, you will see the big gun waves even though you are off a little. V1,2 and 6 should be easy, V 4 will take the imagination to line up. V3 and 5 should be easy after that
8 - Limit your eyeball time on the chest with the younger crowd... they can tell.
9 - Older folks usually welcome a 12 lead and are far from shy.
10 - Have a some alcohol wipes available for those grande versions that maybe caked with talc powder.
11 - Most importantly.... be professional and give every bit of decency to the pt. Medics have been accused of things due to inappropriate behavior.... even the ones that are not intentional. Why risk it.
My first 30-40 times were a learning experience, and it gets easier and your tactics get better, soon its seconds nature and you no longer go home at night thinking about the experience ( whether good or bad... )