The Experienced Method really isn’t difficult. Once set up, the work progresses very smoothly; in fact, I think that ultimately it's easier than working 4 borders separately. First, start by reviewing all the general comments in this post. Then follow on here.
There are 2 things to remember. Firstly, you are creating garter-stitch fabric in rounds, so you have to alternate knit and purl rounds. Fortunately, there is no patterning on the purl rounds (and each purl round is an even-numbered round), so it’s smooth knitting…um...purling.
Secondly, on each knit round (and each knit round is an odd-numbered round) you are increasing 2 stitches at each corner to shape the borders, one stitch on either side of a corner stitch specifically allocated to that purpose. That corner stitch is indicated on the far right, in grey, on the charts on page 5 and 6 of the pattern.
So, to set up the stitches for the borders, start with the right side of the square facing you, and the stitches remaining from the square at the top. Knit across them; they are the 117 stitches for border 1. Then knit up 1 stitch per ridge down the left side of the square for border 2. If you wish, see my comments in the Easy Method for doing the knitting-up along this edge. You should get 119 sts knitted up.
Then work across the stitches in the cast-on edge for border 3. See my comments in the Easy Method for doing this. You should get 117 sts here, possibly 116; aim for 117.
Finally, for border 4, knit up along the remaining in edge in the same manner that you did for border 2. You should get 119 stitches. Put a marker on the needle to indicate the beginning/end of the round.
Take a deep breath to relax and purl 1 round. Divide up the stitches, as Sharon instructions: 118 per side. If you find you are short or over by 1-2 stitches on a side, don’t sweat it. Just make a note that you will need to correct that later.
Okay: you have now completed the first 2 rows (rounds, really) as indicated on the chart I show above, and you can work the next 2 rounds to form the break pattern. If your stitch count is off on a side, simply replace a “K2tog” with “knit 1”. When you have completed the 2 rounds of the break pattern, start working the chart on page 5.
Now the gist of this chart is that each border begins with a corner stitch. On odd numbered rows, you work a YO on either side of this stitch, and these YOs are purled on even-numbered rows. Once you understand how that works, you can easily follow the charts. If you’re going to knit a round it will be an odd numbered round, and you will work the increases as well as the patterning. If you are going to purl a round, there are no increases and no patterning. It’s just mindless purling, so relax and enjoy it.
The one tiny improvement I’d suggest is that I’d setup the borders so that the corner stitches are at the end of the border, rather than the beginning. As Sharon indicates, the corner stitches come from the very first and last stitches knitted up along the sides of the square. If you start the beginning of the round as a corner stitch, that stitch is coming from one of the stitches remaining from the centre square, and things will be skewed by 1 stitch. If this fusses you and it doesn’t make sense, don’t worry about it. It’s a very small point, and in the end likely not very noticeable. Experienced knitters can try it and will see what I mean.
Now, when you complete round 4, you will need 122 sts per border. If you are short or over, adjust the decreases in Round 5 as indicated above in the Easy Method. Then your knitting should be smooth and enjoyable.
One last thing. Sharon has knit rounds 90-92. That will change the fabric from garter stitch to stocking stitch. I don’t know why that would be, as there’s no stocking stitch anywhere else in the design. I’ll knit round 91, and purl rounds 90 and 92.
I hope this is all clear. If not, please ask questions.
See you for working the edging.