I bought 2 meters of a striped jersey knit fabric for the dress. I always like to pre-wash my fabric before I start a project. For the skirt I cut out a circle skirt, I have a pattern template made up for 1/4 of a circle that i always use for this purpose. Fold your fabric in half. (The purple fabric is just for demo purposes)
Then in half again so you have four layers of fabric.
On the corner where the fabric is closed is where you want to cut the hole for your waistband, its always better to cut small try it on then cut larger as needed, if you cut too large a hole you can't go back. If you do happen to cut your hole too large you can always gather slightly before attaching to the top. The size of hole all depends on the amount of stretch in your fabric, some jersey stretches much more than others. Personally I just cut and try it on till I get the fit I want. With a stripe fabric you want to make sure you don't cut the waist hole too tight or it will cause the stripe to stretch out and look unflattering when you put it on.
For the length of the skirt you need to measure from where your bust line will end to where you want your hem to be. My bust line is high on this dress and I prefer my skirts on the longer side so I made my skirt as long as the width of the fabric would allow for.
I'm not a big fan of halter tops so I took a dress I own that I really like the top of and I traced the front and the back of the top onto paper to create a pattern, make sure you add seam allowance onto your pattern so its not too tight once sewn together. You can also use a t-shirt or tank top, whatever you have that you like the fit of.
I serge the sides of the top together then the shoulder seams. I like the serger for stretchy fabrics but you can also use a stretch stitch on your sewing machine. I then pinned the skirt to the bodice, making sure to line up the stripes in the centre of the front and back of the skirt with the centre front and back of the top otherwise you lose the stripe effect your going for. Once you have it all lined up you just sew the two pieces together. To finish it off I hemmed the sleeve holes and back of the neckline with a stretch stitch on my sewing machine. For the style I went with the front of the neckline did not need hemming as it has an excess flap of fabric that tucks into the neckline. I chose not to hem the dress, as its a jersey knit the fabric will not fray so I left it as is to give it a clean edge, just make sure you have a clean line cut around the hem and no jagged scissor edges if you choose to go this route.