I can’t picture what a project will look like before I make it. So I need to try different colours live before deciding what I think looks the best. Like when I made the Mandala Style Placemats.
To be able to play around without wasting yarn you can use this method:
Instead of cutting youryarn when it is time to change colour hook your loop to a stitch marker (a safety pin will also do just fine!). Like this (pics from one of the squares of the Moogly CAL 2015):
Then just keep on crocheting with your next colour and do your colour changes as above.
When it is time to use a colour that is already in the project, measure out how much yarn is needed to weave in ends and double it. Then start crocheting with this yarn at that point in the yarn (this sounds way more complicated than it is!). You will end up with a big loop of the yarn in the back of the project, like this:
Since you don’t cut the yarn between colour changes you can just unravel if you are not happy and try another combination.
When you are happy and done you just cut the long loops on the backside in the middle and pull out the stitch markers. Weave your ends in.
Some stitch markers will end up at the front of your work and the yarn ends will also end up in the front when you pull the stitch marker out.
Just pull them to the back of the work with your needle before weaving them in.