Ok, so you only really need 2 main ingredients to create slime: PVA glue and activator. I know what you're thinking... What is this 'activator' that everyone keeps talking about? After lots of research into various activator products, we opted for using sensitive contact lens solution as our activator. (I figured that if it is mild enough for something you put in your eyes, then it should also be mild enough for my childrens' hands.)
You start with the glue and gradually add activator, stirring and prodding and folding the slime until it is not too sticky to touch and eventually hold. Not enough activator = Sticky slime. Too much activator = Brittle, non-stretchy slime.
To make the slime making process super fun, we also add food colouring (not too much or your hands get stained), sensitive shaving foam (to make it fluffy slime) and glitter (because we all love some sparkle in our lives)! You can basically add these as you go along, although Zara recommends adding them before the activator!
If you are nervous about making slime, watch my daughters making it first and then go for it! You are guaranteed to have fun (but wear old clothes and don't make it over carpet just in case)!