Perming and straightening cause a good deal of damage to hair. Use these tender-loving-care practices after you process your hair:

Hold off on styling or shampooing for a week after processing.

Use a mild shampoo and the strongest conditioner you can without making your hair go limp.

Wash your hair only as often as absolutely necessary.

Do a deep-conditioning treatment once a week, if possible.

Minimize further damage by combing gently (especially when wet) and keeping heat-styling tools on low.

A drop of silicone serum can help smooth down the cuticle and add a bit of shine.

Care to be taken while colouring permed or straightened

Your hair is already somewhat damaged from perming or straightening. If you feel you must color it too, use the gentlest process possible. Highlighting and changes of more than about two shades are best done by a professional colorist. If you want to try it on your own, use a gentle semipermanent color or a temporary one and carefully follow the directions. Keep in mind that permed or straightened hair is more porous than normal hair, so it absorbs dyes more quickly. Always do a strand test to get the timing right.

Curls Like a Perm
All it takes is hair that is slightly dirty and some great styling products. Freshly washed hair doesn't tend to do as well, most likely because the hair shaft surface is too smooth. So, try shampooing and conditioning the day before doing your hair. Pop a light gel into your hair and work it through the ends and dry as usual (in this case, slight product buildup is a good thing!) The next day, give your hair a light touch of hairspray. Then taking small sections of hair, start working the curling iron through your hair, letting each curl cool completely. Once your entire head is finished you can choose to loosen the curls with your fingers for a tousled look or use a brush for a smoother look. Spray again with hairspray.