Here's a classic blues scale and barre chord riff for you to learn from Eric Clapton's 60s supergroup Cream.
The first half of the Sunshine Of Your Love riff is based on the 10th position 'shape 1' blues scale. This is simple enough but don't forget to change position to reach the 8th fret F note (although, to be honest, there's no reason you shouldn't play the F on the sixth string if you prefer).
The second half is more aggressive, with those staccato barre chords and vibrato on the high F really driving hard. Try not to pick too loudly here or the single-note part of the riff may sound weak by comparison.
For your tone, select a neck humbucker on your electric guitar and turn the pickup's tone control down between 0 and maybe as much as 3, depending on how bright your guitar sounds. Assuming you aren't in a position to max your amp out, set it to a suitable volume level with the tone controls in the middle and adjust to suit.
