As a rule, I usually don't make summer knits. As I see it, there is a time and a place for everything, where winter is for thick, cozy knitwear and summer is for clean, lightweight sewing projects. This way you not only get a thinner, airier product, but you won't be stuck all day with kneedles and yarn between your sweaty palms. I also think most warm-weather knit patterns are really quite ugly, or else I lack the imagination to see their potential.
Nevertheless, in the summer after I learned how to knit I created this quite simple green halter top piece with overlap in the front and an intarsia pattern on the chest. I can't say it is any better than anything else out there in terms of warm-weather knits, but if that is your thing then this is a really easy piece that is good for some intarsia practice.
Yarn: I used worsted weight yarn in an acrylic or cotton blend, but a finer yarn will probably make this a sleeker, more summery top.
Intarsia: I made my own hibiscus intarsia pattern using internet-generated graph paper to draw my own design.
Pattern: Retracing my steps, this is how it goes as far as I can tell. Feel free to improvise.
The body~The body is knit in the round, starting with a few rows of garter stitch at the botton followed by stockinette stitch for the rest. If you like a rolled hem, skip the garter stitch and knit a few extra rows of stockinette. Knit from the desired place on your stomach or hips and stop without binding off right below your breasts. I added some decreases in the sides for waist shaping by putting a k2tog at the beginning and a ssk halfway through every 4th row (half inch). To fit my waist, I started the decreases about 2 inches up and stopped them 2 inches from the top, but you should adjust it to fit your body and style.
The boobs~The next step is to bind off the rows that constitute the back:between the decrease stitches for the waist, I bound off the back half of the top save for about an inch and a half on either side (increasing this width will give more breast coverage under the armpits, while skipping this step will reveal more). Next, divide the stitches onto two sets of needles by putting about 3 1/2 inches on one needle and the rest (the majority) onto another.
For the first side, put the 3 1/2 inches on a holder and shape a triangle on the other stitches by knitting a k2tog at the start and a ssk at the end of every 4th row (1/2 inch). To make sure that the sides don't curl, I would recommend creating a selvedge by knitting the first and last two stitches of each row in garter stitch (and putting the decreases inside of those). Continue until only 4 stitches (3/4 inch or desired thickness for neckband) remain. Place the stitches on a holder. This is the overlapped side of the breast, and does not have any intarsia on it.
Using the needle with the 3 1/2 inches of stitches, pick up stitches from the base of the other triangle until you are 3 1/2 inches away from the bind-off at the back (about 6 inches of picked-up stitches for my small boobs, or almost the entire way across the front of the shirt). There should now be as many stitches on the needle as there were for the first triangle. It should also overlap in front of the other one, and is the place for your intarsia pattern. Shape the triangle the same as for the first one, adding in other colors for the design.
The neckband~When four stitches remain on each triangle, continue to them knit evenly in stockinette stich until the two connect around your neck. The length of the neckband is important to the overall fit of the shirt, so definitely try it on in the process. When the two pieces are the right length, use the mattress stitch to bind them together. If the sides curl, once again it may be desireable to use garter stitch instead of stockinette stitch, either to border a wider strap or to knit the whole way across.
Sew in all the loose ends and enjoy your warm-weather creation.