Beyond classical guitar strumming [rasgueado], I never once learned a 'strumming pattern'. I learned by feeling my way into a rhythm. When asked over decades, 'so what's the strumming pattern', I always answer the same...down-up. What the actual strumming pattern is of any given song is relevant only after you can make chord transitions with your fretting hand, while your strumming hand does not stop. If you can't strum and change chords without stopping, working on strumming patterns inhibits rhythmic development.
To play different strumming patterns, we listen to the recording and strum it like we hear it. We allow this to be natural. We don't think in symbols when playing rhythm. We strum. We miss when we feel there should be a gap. Strumming patterns change within songs, as drums do [beats, fills, etc.]. Trust me, strumming in different rhythms happens naturally. There are many variables to an overall strumming texture: hit-miss, accents, ranges, changing elements, palm muting and palm mute bouncing, and press-touch. Micro-managing all of these variables is tedious, if not impossible.
We highly recommend using your musical rhythmic feel to strum what you hear, rather than counting things out and needing them written out in symbols. The only time, as a coach, that I ever write out strumming patterns is for students, when/if they ask [and as proof that, in the beginning, trying to miss is not the way to train].
You already know, intuitively, how to strum and create patterns. And, we can strum any song in any rhythm. Core idea: you know how to strum and create rhythms, so just be natural in your approach. It happens.
Strumming patterns create different motor rhythms through hitting and missing. We have included a handful of common patterns below.
The basic principle with strumming is that the strumming hand never stops moving. Even though it might miss, the hand keeps moving. For these patterns, use any chord, open strings (the open chord), or a mute (lightly touch to create a clunk).
Strum this a few times and immediately move to strumming 8ths. Notice that this pattern is a hit-miss. When you miss, the hand passes across the strings without hitting (or awkardly whipping the hand).
Once you master this (make it automatic), then learn to miss without altering your strumming motion (like changing speed on a miss, or whipping your hand awkardly to miss).
Missing on the & of 1 and the & of 3.
Missing on the & of 1 and the & of 4.
This is the world's most used strumming pattern. We miss on the & of 1 and the downbeat of 3 [an 8th rest indicates the miss on beat 3 - we can let the chord ring or hush it with a mute - typically, we just let it ring].
Here is a pattern in 3/4 time. We can also miss on the & of 3.
And here is a pattern, hitting down on all the beats. This example is in 6/8 time. We put the accents typically on beats 1 and 4 and play these as triplets.