Selling your clothes isn’t just great for the environment, it also helps free up space in your wardrobe (for more secondhand clothes).

When asked for tips for selling unwanted clothing, Guardian readers suggest online marketplaces including Facebook, Vinted and eBay. But first, consider selling or giving to friends who might be the same size.

Charities are also a great way to recycle fashion but readers suggests thinking beyond the local op shop to favour organisations that specialise in workwear for job hunters or even theatre schools who might looking to top up their costume supplies.

No matter how you get rid of clothes, most readers agree that the sooner you do it the better, and that effectively cleaning every item before selling makes a huge difference.

1. Price clothes to sell

No way do I want old clothes hanging around for as much as “a year” while I try to rehome them! By using eBay and Vinted, it’s possible to reach a big audience and sell almost anything in a couple of weeks, so long as you price realistically.

Where sellers go wrong is in assuming that an item’s value now is defined by what they paid for it in the past (the “sunk cost fallacy”). It isn’t.

Instead, if you want a piece to actually sell (and not just languish in a corner), the price has to reflect what a buyer is willing to pay for it. You must accept that you’re not going to recoup the full purchase price – which is only fair: you’ve worn and used the piece already. Even if it’s new, you aren’t offering the refunds or consumer rights of buying in a shop.

Looking at prices for sold items from the same brand (as both eBay and Vinted let you do) will help you price realistically. For sought-after brands, 50% of the “as new” price may be possible – for mass-market high street brands, 20% to 30%.

Low-quality fast fashion is vastly over-supplied and much won’t sell at all. Perhaps you shouldn’t buy so much of it, then …

– Jay, London

2. Look to friends

I have found success matchmaking, if you will, my clothes with friends and relatives. Even friends of friends. I inquire if someone has a young child, or is my size, likes a certain style of clothes – and I have found new owners for my castoffs. It helps to make sure that the item will be actually used and worn so match things to people that suit their habits, for example, machine washable items should go to lazy friends.

A big help is learning to sew and knit. Which, once you bother to start, can open many avenues of usefulness. So many good clothes get thrown away because of one or two little snags, holes or stains. Even beginner can fix these with just a little time and effort.

Also, for specific pieces like costumes or tricky-to-sell vintage clothes like cheap rabbit fur or well-worn gowns, try donating to independent theaters, school theater groups or costume shops. And for good-quality items like vintage dressing gowns, scarves or sweaters, consider donating to care homes or centers for elderly people, and even to museums.

– Adrienne, California

3. Seek out specialist charities

I have a set routine. Great pieces get offered to a couple of friends who are the same size and share similar minimalist styling. High-quality luxe brands I resell on Vestiaire which is also my go-to circular fashion site to buy from. Lightly worn workwear goes to Dress for Success. The balance of more casual brands worn and unworn (shame-faced emoji) goes washed and pressed to the Wayside Chapel, a local charity that raises money for people in need in my community. I used to shop there myself as a student so it’s nice to stock the store these days. Nothing to landfill if I can help it.

– Anonymous, Sydney

4. Keep clothes clean

Look after them while they’re yours! Treat your clothes as though you want to keep them forever, repair them when needed, keep them clean and stain-free. If you want them to go to a new home, be prepared to make a loss on what you bought them for.

For me, the purpose of onselling clothes is to make sure they go to a loving home, declutter and then make some cash (it helps me come to terms with the money I sometimes waste on clothes!). And buy second hand – it’s only a circular and sustainable market if you participate in all aspects of it!

– Anonymous, Wellington