When I need something to just make for the satisfaction of getting a finished object off my needles I have two "go-to" projects - dishcloths and charity squares. I reckon I have enough dishcloths for the time being so this evening I will be knitting charity squares.
There are lots of charities that need knitted goods. Some want hats for premature babies. Plenty of animal charities welcome blankets or coats for dogs, cats, even horses. Some food banks and homeless shelters accept knitted goods. Even non-knitters are likely to be familiar with the Innocent smoothie knitted hats for Age UK after seeing bottles wearing miniature knitted creations in the supermarket.
Personally I like to knit for Knit-A-Square. This charity asks for 8" squares to be made into blankets for AIDS orphans in South Africa. You don't need to make the blankets - the charity does that - all they ask for is squares, as few or as many as you can manage. The more eagle-eyed among you will have spotted that there are crocheted squares in the photo as well. Crochet is fine too, as long as it's not too holey because they don't want to let too many draughts through. They also ask for basic garments, hats, vests, simple sweaters, and hand warmers (like fingerless mitts) and patterns can be found on their website that are suitable even for beginners.
One reason why I choose to support this charity is that it doesn't try to provide something that other organisations are already working towards, such as housing, food or healthcare. They are aiming to provide something more human than that - a cuddle in knitted form. We often think of South Africa as a hot country, but it has its winter too, and it gets cold at night, and a child without shelter is vulnerable. A warm blanket, a hat and a woolly vest and sweater gives a child a much better chance in the cold, and hopefully it lets them know someone somewhere cares about them too. Supporting this charity is something I can do to benefit myself - I can use up stash oddments, clear room for more yarn for me, and rest my brain while still knitting - while benefitting children on the other side of the world with a simple square or two that costs me little to nothing but for some time.
Surface mail postage to South Africa is surprisingly good value, and I usually pop in some crayons or coloured pencils, children's underwear (new but removed from its packaging so it is effectively "used" for customs/import purposes), simple knitted hand puppets or toys to go along with my squares and garments.
If you're looking for a charity to knit for, especially if stash busting is your goal or you want a group project for a knitting group, do consider Knit-a-square. They have a Ravelry group here too.