The key to using these items on a masculine card is to first pick colors and shapes that are suitable for the male receiving your card. Colors and shapes like these work out great:
Shades of green, orange, and yellow would also be great color choices.
The other thing to remember when using items like these on a masculine card.....less is more. Crisp and clean lines, and simple rows of jewels work best when trying to keep the card from leaning towards the feminine side.
I know...I am totally teasing you by showing two little clips from my cards!! So, without further ado....here are my father's day themed cards using jewels (& ribbon!!). Notice that they are completely appropriate to give to a man, jewels and all.
So, go ahead and add some jewels to your masculine themed cards!