Watch the Level 4: Blues Bends online guitar lesson by Jeff McErlain from Take 5: Blues Bends
Bends and vibrato are very physical and require hand strength that needs to be built up over time and practice. I cover those techniques in the first video, and since we live in the information age of direct gratification, we have things like YouTube where we can watch just about every guitar player in our living room.
So instead of watching some fools taking hot pepper challenge videos, use your valuable time watching great guitar players' hands. I have learned so much from watching other people play. For example, Eric Clapton's vibrato is physically very different than Jimi's, or Jimmy's, or Eddie's, or Stevie's. By examining all of these guys, we can expand the way we vibrato and come up with our own thing.