What is the best thing to write about

Hi, i was wondering what is the best thing to write about in a poem? i've written over 30 poems and i have been wondering if i've been doing this correct. i usually write about love, life, nature but i'm not sure if its always good to write about that stuff. i'm running out of ideas and i was hoping someone could help me out.

Oh i am sorry about my avatar, im trying to find a new pic but it seems to be very picky on what can fit. can you also help me out on that one?

Ty for the answers i seek.

oh and also... is it bad to write poems about religion even though you have faith? i mean because there are people who don't have faith or believe in god or anything and what if it offends them is that bad on our part?

Oh your so right ^_^