Some years ago when I considered knitting myself a triangle shawl. My late friend Haya Meyerowitz pointed out to me the BAKTUS SHAWL. The pattern says one has to cast on 4 stitches on a knitting needle, Knit 2 rows purl 2 rows etc,,,, Thus one makes some `furrows` lengthwise. Every 4th row [=2 furrows], one ads 1 st, I advice not to add the st at the edge of the row but to pick up 1 new st between the 2nd and 3rd st before the he edge.
When one reaches the middle and the wanted height, one starts decreasing 1 st, every 4th row, [I advice to do this between the 2nd and the 3rd st from the edge.] go on knitting in furrows and decreasing until one is left with 4 st on the needle. Finnish neatly.
From my experience increasing and decreasing st never looks `exactly` the same. Besides I had no idea to which length I wanted to make it. So I decided to start the two triangles at the same time on the needle and knit both at the same time and sew them to each other in the middle.
I cast on of 4 st, using one cotton ball and cast on a second row of 4 st using a second cotton ball. Follow the pattern twice every time, remember you are knitting 2 triangles, one after the other. I immediately decided to knit all rows =garter stitch. After I reached 49 cm, I started increasing every 2nd row and thus my triangles rapidly reached 59 cm.
My intention was to knit it least 5 cm or even a bit longer, under my waist line. [Thus please measure yourself or the recipient from neck to waist].
When I reached the length I wished for I knitted the rows from beginning to the end. About every 5-7 cm I knitted a short row of 6-10 st, turned and knitted down again. Next row I knitted the whole row. This gives the bottom of the shawl a nice roundish `fall`.
When the straight part measured 28 cm, I added another knitting needle cast on 10 st including the lowest st on the 2nd triangle. Now I knitted 9 st and the last st I knitted together with a st of the 2nd triangle, turn work, return last st to the left needle, knit 9, knit last st together with one of the other triangle, go on knitting like this till you have finished all st on both triangles, and connected both triangles into one shawl.
I adorned my garter knitting by sporadically making `holes` of either one st [k 2 together loop over needle next row knit loop as if it is a st.] or two st [knit 2 together 2 loops over needle knit 2 together, next row knit the double loop with 1k 1 p.].
on my next shawl [a present for a friend] I knitted the full wanted length for the bottom [59 cm + 5 st] and sewed the two triangles together in a hidden st.
You can Finnish the shawl either by crochet or knitting a nice lacy edge.