In case you want to finish your Wrapped in Jamie project at the end of Season 1 of the CAL, here are two ideas you may want to consider for your squares.
Using them will be beneficial for the correct stitch count for a suggested border.
To use the border I designed for Season 1, I recommend a join that keeps the squares close together.
The Project Border is flexible to be used for a 2 x 6 or a 3 x 4 squares layout or even for 1 x 12 with only 1 stitch added above the join in the first round.
Joins that will work for the WIJ Project Border
Whip stitch join
Mattress stitch join
I am not really a fan of sewing squares together, so my go-to joins would more likely be one that can be crocheted.
All of these joins are worked by taking (part of) a stitch from one square and connecting it to (part of) a stitch of the second square.
Flat “Zipper” join – this will bring your squares together in a very flat manner and at the same time create a neat visible seem of top loops.
Demonstrated in detail by Dedri Uys at Look At What I Made
Zig zag slip stitch join – Similar to the ‘Zipper”-method and the slip stitch join, but with a little twist. A great join to emphasize a ‘Celtic’ look.
Single crochet join