Take some time to read the ghd reviews of each manufacturer on this web site. There are many top rated ones available. The best flat iron is the one that has the functionality you want, the weight and feel you want, is easy to use, at the price you can afford, and that straightens your hair to perfection.
Always read the manufacturer's instructions. By using it as the manufacturer has specified you will lengthen the life of the appliance and will get the best results.
Practice using it while it is still cold. Every brand handles differently, so even if you've used one before, you should still take it for a test run.
Use an anti-frizz spray, lotion, or serum - usually a silicon based product. This should be applied while the hair is still wet. If done correctly on wet hair, the lotion will soften hair as it dries - don't put it on dry hair or it may become "greasy".
You should make sure you hair is completely dry before you use the appliance. Use a blow-dryer and don't worry about trying to straighten it - that comes next.
Only use the tool on small sections of hair. Use sectioning clips,if you have them; sections of around two inches usually works best. The thinner the sections; the flatter and lighter your hair will be.
Remember: flat irons are very hot. Apply pressure evenly and move the flat iron in a downward direction, at an even,slow pace.Never stop moving the flat iron! You will burn your hair.
Use a wide bristle brush on your hair while brushing your desired shape into place.