All I have ever used is monokote. I have learned to get the edges sealed down (except for a little spot on fully sheeted surfaces). Then I get the heat gun out to start heating it and the use the hot glove to press it to the sheeting or cap strips. As you heat the covering that is over the sheeting it will wrinkle a little, then with a little more heat, it lays flat. That's when I press it down and stick it.

The cap strips are the same, just need to be more cautious cause too much heat will burn holes in it fast.

Just take your time and it will pay off.