Best way to stop mirrors steaming up please?!

[YumeeMumee]

I thought I saw a thread suggesting ways to stop mirrors steaming up but I can't find it

Can I have some suggestions please!

Washing up liquid.

Just a few drops. Smear all over mirror with a dry cloth/piece of kitchen roll.

I find it stops the bathroom mirror steaming up for about a week.

shaving foam

Excellent - thanks!

apparently if you wipe it down with dry tissue and then add a few drops of shampoo to the tissue and wipe it over it works (guess this is similar to SaintG's, though)

Washing up liquid or any form of liquid soap works, wiped over with a dry cloth or tissue.

Works for glasses too.