Staples of Trap

I'm new to trap production, but I've been listening to it for about 8 months now.

What are the general staples that are in most trap productions?

To me, it seems like there is always:

• Snare on beat 3
• Rolling Hi-Hat with pitch bend
• Sparse 808 groups
• Cowbell lead
• "WHAT" samples on upbeats

What types of chords, rhythms, and instruments are common to generic trap?

EDIT: Formatting