Correct fretting for patterns like this

[Rich44]

Where you have for example:

A --5--
E 5---5

Basically patterns including the root and its fourth(?), how do you fret them. I can think of three ways but I've never been sure the proper way to do it:
1. With a single finger holding both frets down (kind of hurts though)
2. With a single finger moving to each fret (difficult to move quickly enough)
or
3. Two fingers - first finger about a quarter of the way up the first fret, next finger to fret the other (e.g ring finger on first fret, pinky on fret behind)

I've made a stupidly simple thing sound complex I know, but any help is appreciated. Tah

[Doddy]

It depends on the speed of the piece as to how I'd play this. Generally,I'll use one finger to play both notes by moving it
rather than barring,although if it was part of a fast semi quaver thing I may use two fingers.

[Stewart]

Invariably 1 - But changing the angle/shape so that I'm muting (or partially..) the string not being played

[chris_b]

I've no idea which one is "correct" but depending on the number, speed and where I'm going next I'd use either of your 3 examples, and probably wouldn't be able to tell you which one I'd just used.

[mcgraham]

[quote]Generally,I'll use one finger to play both notes by moving it
rather than barring,although if it was part of a fast semi quaver thing I may use two fingers[/quote]

I do the opposite. At slow speeds (or fast alternating between adjacent strings) where each note needs to be separate I use two fingers, one for each fret/string.
At moderate speeds, generally where there's a note in between two on same fret/adjacent string, I'll use the same finger and move it.
At high speeds where it's part of a longer phrase, I use 'finger rolling',... which is similar to using your finger as a barre, but involves rolling it in a way so as to only actually fret individual songs (as classical/jazz/rock/metal guitarists would do).