You don't -need- a sewing machine to make beautiful loli clothes. However, handsewing has its own set of skills:
There's no way I can condense it all down to one livejournal post, so this will be simplified a great deal. I'll list books to check out for further information at the end.
First, the three most important stitches:
The most basic is the running stitch. Running stitch is used for gathering, for decoration, and for sewing seams that don't take any stress and don't need to stretch(the side seam of a full skirt is an example, as is lace affixed to a hem.) Everyone knows how to do this stitch; it's the simple up-down stitch that we all learned on sewing cards when we were children, and it's what we use for mending and hemming when we don't know any better and don't care how it looks. Nonetheless, one needs to practice it if one wishes it to be perfect.
Backstitch is used for seams that take stress and seams that need to stretch slightly, as well as for attaching beads. It uses more thread -- at any given point there are three threads along the seamline at once -- and is therefore slightly stiffer than running stitch. To sew this stitch, start with two running stitches, one on the right side and one on the wrong side. Then, when inserting your needle back down into the fabric, insert it behind where the thread comes out, instead of ahead as you would in running stitch. Backstitch is the stitch you'll probably want to use the most, since it is stronger and less easy to unravel than running stitch. Backstitch can be sewn with the stitches on the top side either touching each other (in which case it will look like machine stitching) or separated (which appears similar to running stitch.)
Slipstitch is for hems and facings, and when done right it is completely invisible. On a folded and pressed hem, pick up just one thread of the garment, pull the thread through, and take a small stitch through the fold of the hem. Do not pull this stitch too tightly; the hem should lie in back of the garment fabric and not pull at the outside, visible part of the garment.
Next, Handsewing tips and tricks:
-Hand stitches should be tiny, tiny, tiny! Ten to twelve stitches per inch is the bare minimum; eighteen to twenty-four stitches per inch is best. Use smaller stitches on lighter and more tightly-wove fabrics, and larger stitches on heavy or loosely-woven fabrics. Whatever your stitch length, make it as even as possible.
-Wax your threads to keep them from knotting and tangling. Use the special wax you can find at the notions counter, or a block of beeswax; even an uncolored candle will do in a pinch. Run your thread over the wax, and then press it on high so the wax permeates the thread, and your threads will be stronger and easier to sew with.
-Don't try to sew with three feet of thread on your needle; it's easier to pull a shorter length through the fabric without tangles.
-Don't begin your seams with a huge knot; take several tiny backstithes in the same place instead. If you have problems with the stitches slipping out, tie a knot, take the backstitches, and then cut off the knot.
-Handsewing gives you more control than machine sewing, but it also takes much, -much- longer. If you're finishing any reasonably complex hand-sewn piece in four or six hours, you're probably doing something wrong.
-Don't take shortcuts! It takes just as long to stitch your hem messily and then try to disguise your mistakes with a ribbon or lace ruffle as it does to slipstitch it beautifully to begin with.
-Keep in mind which details are worth hand-sewing and which aren't; try embellishing with embroidery or cutwork bound with buttonhole stitch instead of with pintucks and ruffles.
-Don't give up! It may be frustrating at first to sew twenty perfectly even stitches in the space of one inch, and then realize that you have twenty inches yet to go -- but each stitch improves your skills just a little bit more, and by the end of that seam it won't seem difficult at all. ^o^
-The Complete Book of Tailoring by Adele P. Margolis explains how to hand-sew coats, jackets, and suits.
-Couture Sewing Techniques by Claire B. Schaeffer also has a chapter on tailoring, but goes more into the dressmaking side of things.
-Older sewing books usually have more explanation of hand-sewing than modern ones. I reccomend the Singer Sewing Book (my copy was published in 1947). It doesn't cover the garment construction side of hand-sewing as much as the previous two books do, but for finishing techniques it's invaluable.
The important part is to realize that just because it's hand-sewn doesn't mean it has to look homemade or inferior. The virtue of handsewing is that because it takes longer than machine sewing, you have the time to consider each tiny stitch, and the control to place them -exactly- where you need to in order to achieve the result you want.