Vibrato. Anytime you have a note and you hold it for a little while, it sounds nice to give it a little bit of vibration. It's a lot like singing. So if somebody sings a note, you don't want them to vibrate it right away otherwise it sounds funny. Right? But if you hold the note, then add vibrato, it's much better.
The same thing is true of guitar. So I'm going to take a note here and I'm going to give it a little bit of vibrato after I've held it for a second. Okay? Same thing can be done with a bend. It's a little trickier, but here's an example.
So what I try to be able to do is vibrate it with different tempos. If I'm playing to a tempo like this, I'm actually thinking of triplets there. One two three, one two three, one two three, one two three, one two three, one two three. I might try eighth notes, sixteenth notes. These are all good exercises for practicing vibrato. But ultimately, it should come really naturally and it should happen after you've held the note.