Are There Any Rules For Ironing?

Ironing is very simple, but may take some practice.  As a general rule, always look for the care label which is usually found in clothes, which will tell you the heat setting at which it should be ironed.  Do not use a higher heat setting or you may scorch the clothes.  
Iron wool using a damp cloth between the wool and the iron.  This will help minimise any shiny patches.  Always iron silk on a cool setting and never iron velvet.  Velvet should be hung up in a steamy atmosphere such as a bathroom to get rid of the creases.
Always iron embroidery on the 'wrong side' (the front of the embroidery should be face down on the ironing board).
Towels should not be ironed (not only is life too short, but it ruins their pile and will make them flat and lifeless).  If ironing trousers which require creases down the front always use a damp cloth over the trousers, or you may end up with a shiny finish to the trousers, particularly at pockets and seams.

I use an ironing cloth and that protects the material and i will not scorch. Ironing clothes are just another  layer of protection. You can think of it as a firewall.