Lifelines are simply scraps of yarn fed into your knitting, and they are (in my humble opinion) the easiest way to fix mistakes.

However, I'm talking about proactive lifelines, which means that you have to pre-empt a mistake. Prevention is the best cure after all!

What this means is that you have to insert a lifeline into your knitting before a mistake occurs, and you have to keep putting lifelines into your knitting throughout your project. It's a bit like backing up data from a computer onto a hard drive; you have to do it regularly, just in case something goes wrong.

Unless you are a total beginner, I wouldn't recommend doing this for basic knitting projects i.e. when you're just using a simple stitch such as garter stitch or stockinette stitch. Instead, I would recommend that you use lifelines in more complicated knitting projects, or in projects where you lack confidence.

Usually, I place a lifeline before and after doing a particularly tricky bit of knitting, so that I don't feel too nervous of making a mistake whilst knitting, as this can lead to procrastination.

As the video below demonstrates, if you do make a mistake after placing a lifeline, it's really simple to then unravel the knitting back to your lifeline without a fuss: