Although I have not yet learned the art of men's tailoring, I have made several of what the old sewing books call "dressmaker suits." These suits are not as structured as a man's suit, but still require sewing skills beyond the ordinary dress or blouse.
A dressmaker suit or tailored suit is not a project for beginners; however, it is certainly a project within the reach of anyone with strong sewing and pressing skills. With quality materials and the proper pressing tools, a patient home tailor can produce a suit she will be proud to wear to office, party, or church.
To begin, one must know that quality suits are not made of shoddy materials. The best fabric for tailoring is wool. Wool can be easily molded and shaped with steam. Proper interfacings are also essential. Consult your pattern envelope for recommendations. Websites selling sewing supplies are also sources of information when choosing the right interfacings for lapels, waistbands, and collars.
Once quality materials are on hand, carefully cut and mark all patterns pieces from fabric, lining, and interfacings. Tailor's chalk comes in white and colors, and is good for marking smooth fabrics. Tweeds and other textures are better marked with thread tacks. Use different markings for small dots, large dots, and squares, because you will have to match all those markings in order to fit the pieces of your suit together correctly. Tailoring leaves no margin for guesswork; mark accurately! One of the most important markings is the "roll line" which is the line on which the lapel of the jacket folds back against the jacket front. Use a line of basting to mark the roll line.
Carefully follow all pattern instructions, in order. Don't try to "wing it" until you have made a dozen suits or more. Press as you sew. Your pressing is at least as important as your sewing. With wool, use a damp press cloth and press on the wrong side of fabric. Use enough steam from your iron to shape the fabric, but not too much. Overpressing can cause shine or shrinkage. Press curved edges over a pressing mitt or a tailor's ham to get the correct shape. Use the wool setting on your steam iron and do not touch the iron directly to the wool. For fusible interfacings, follow the manufacturer's instructions. Proper pressing tools are available in the notions department of most large fabric stores.
Careful attention to finishing details is the final step on the way to your suit. Consult a sewing book for directions for bound buttonholes or follow the instructions for your sewing machine's buttonhole feature for worked buttonholes. Make test buttonholes using scraps of your fashion fabric, making sure to add the same layers of interfacing and lining as that of the actual suit. Test your buttons to be sure you have sized the buttonholes correctly, then make the buttonholes on the suit. Finish any exposed seams with seam binding, overlocking, or a Hong Kong finish. Sew on buttons, hem the pants or skirt, and enjoy a suit that looks like it came from a custom tailor.
The information on pressing I learned from a 4-H book published circa. 1976. Rupel, Annabel J., "Clothing V, VI & VII," Cooperative Extension Service, Purdue University, West Lafayette, IN