Oh - and something the washing machine engineer told me: if you're using those sachets, use one and not two, and if you're using liquid/powder, use half the recommended amount. He claims that you don't need as much to get clothes clean in modern machines, and it makes them less likely to clog.
Don't use washing machine cleaner either, if you're feeling inclined to - a cup of white vinegar in a hot, empty cycle cleans things up and gets rid of remnants of fabric softener etc
Also - cheaper than anything else: buy an Ecoegg from Lakeland (sometimes they have something similar in Lidl, though I've not seen them in a while) - it's a plastic container with little ball things in, and you use it in place of detergent. It gets clothes clean, saves you itching from powder, is good for the environment - and lasts for ages. I've had mine for just over two years (I do about ten loads of laundry a month) and still don't need a replacement - before that, I had the Lidl one for about two and a half years before it needed replacing (and that was just because the plastic cracked: there was still a set of replacement filling) They can be pricey to start off - Lakeland's is about £8, I think - but pay for themselves very quickly.
If you can bear the noise, too, chuck a couple of pound shop tennis balls in your tumbledrier (if you've got one); it makes clothes fluffier and gets them dry much quicker. (Another tip from the washing machine guy -apparently, it's noisy but not harmful: I have no tumble drier, so I can't comment!)
