As a beginner (Finally getting into music production, or at least learning) I really don’t know where to begin with things. I’ve flipped through maybe 80% of the expression presets and not too many really stick out to me.
I figured I’d ask and see what some other users like to use 
I haven’t played with arpeggios very much but I liked them a lot and triplets seem to be a go to for me right now, just making basic songs
HI @Talia
Welcome to the forum. It is difficult to suggest a selection of expressions to you as my taste will different from yours, but I would like to suggest a couple of ideas to help you use the expressions.
The number of beats that an expression will play for varies form expression to expression: some are only 4 beats long, some are 8 and some of the motifs are 16 beats long. So you may want to consider changing the number of beats in the settings menu.
You may also want to consider creating a pattern and then applying different expressions to individual blocks (chords). Given that music often based around repetitive patterns with variations you may consider applying the same pattern to three of the blocks, but a different pattern to the fourth if you have a four block pattern. You may want to have a look at Introduction to Using Playback Performances to Give Interesting Melodies.
Hope this helps
I have found a lot of interesting opportunities by using .5 or 1.75 duration expressions, chopping them up a bit. I’m doing that on my current piece.
In answer to the original question, I try VERY hard not to have favorite expressions or phrases. My composing skills are limited, and the way I look at it, if I use the same stuff over and over, they’ll stay that way.