What is the Fabric? I often use the fabric to give me guidance. If there is a floral, I would use a leaf & floral free motion meandering, if swirls try &create a swirling design, etc.
Generally, with a straight block, like log cabin, split rail,, I try to use a curved design.
I also use the serpentine stitch built in my machine to stitch in the ditcch. Align the needle up with the seam, & the stitch will go to both sides, creating a curved effect, & if you use a varigated thread it is pretty.
Good luck, relax & enjoy.
Be sure to post when done, we all want to see your 1 st.