Try before you buy
The mistake people make when buying second hand clothing is that they still look for the same sizes that they would when buying brand new. Remember - second hand clothes can shrink or become stretched, so never trust the size. They might also have come from another country with a different sizing system to that of the UK. So, if in doubt, try the garment on for size. Look for what works best for you, and don't rule out something just because it's a couple of sizes too big or too small.
Inspect the item
It's always a good idea to check the item thoroughly before you make your purchase. Look for any tears or rips, or any missing buttons. All of these imperfections are easy to replace, and if you are expecting second hand clothing to be perfect, it's probably not for you. Any larger rips or missing material might be more difficult to replace however, so weigh up whether it's worth investing in a piece of clothing if you won't be able to make any quick fixes yourself.
Wash second hand clothes
Yep, this one's pretty important. You should always wash any second hand clothing before you wear it to get rid of any unwanted smells. Old clothing can also pick up dust and dirt - especially if the garment hasn't been washed in a while. If you've managed to find a vintage garment, always check the label for washing instructions. Throwing a coat or jumper in the washing machine might damage the item - even if it was in perfect condition when you purchased it second-hand.