Paul McCartney's Crochet Waistcoat: Construction

image of front and back view
If you want to make my version of Paul's waistcoat using 4-ply yarn you will need to make 86 squares altogether.  Here is a breakdown...
The back section consists of 6 squares in width by 7 squares in length = 42
The sides consist of two panels in width by 4 squares in length             =16
The front section consists of two panels on either side by 7 in length    =28
                                                                                            Total  =   86

(written in U.K. crochet terms).

ch - chain. 
sl st - slip stitch
dc - double crochet (U.S. terms sc - single crochet).
tr - treble (U.S. dc - double crochet)
tr2tog - treble 2 together (U.S. dc2tog - double crochet 2 together)

Once you've finished making all your squares and tied in all the ends, then you need to neaten around the armholes. I did this by simply making a dc into each tr around. Start with a standing dc at the top of the armhole, and don't make a dc into the ch 1 spaces between the tr clusters as this will result in the armhole becoming too baggy. Also don't work into the gaps between each joining square - you will end up with too many stitches. At the bottom corners of the armholes where 3 squares come together to form a right angle make a tr2tog  starting in the ch 2 space of the 1st square and then finishing in the ch 2 space of the adjacent square. Starting in the same ch 2 corner space you just finished on make another tr2tog. You should have completed 2 x tr2tog. Continue around, sl st into the standing st to finish. Fasten off.
image of buttonhole and borderRibbed Border
I started my waistband on the bottom right hand side. With wrong side facing you sl st into the ch 2 corner space and make a foundation ch of 10 (or however many you prefer). For me this was a nice measurement as it was exactly half the length of a granny square. Dc along the row till you reach the square and sl st into the next tr along.Ch 1 turn (just flip the foundation ch over). Working in the back loops only, dc along the row, ch 1 turn.
Important: Do not make a row from the ch 1 spaces between the clusters, sl st into the next tr instead. Ignore the gaps where one square meets the adjacent square. If you don't there will be too many rows and will result in a frilly border.
Continue all the way around working only in the back loops. Your last row should finish in the ch 2 space of the bottom corner square.

Front Edging & Buttonholes
This is made by simply working a tr into every st, ch 1 and ch 2 corner spaces along. Starting at the bottom of the right hand side of the waistcoat make a tr standing st into the first dc st of the border. When you reach the beginning of the first square instead of making a tr into ch 2 corner space, ch 2 (depending on the size of your buttons you may need to make an extra ch or two) tr into the first tr of the next cluster - this is your first buttonhole. I made another two buttonholes where one square meets the next, so after making a tr into the ch 2 corner space, ch 2, tr into the next square corner ch 2 space. Continue around and finish by making a tr st into each st of the ribbed border, fasten off.