OK, I'm going to say it: Some times the best thing to do is rip your knitting back.
I know it may seem painful, but it's true.
Sometimes a mistake can't be fixed by dropping a stitch down a couple of rows and using a crochet hook to work it back up and it may be easier (or less time consuming) to rip back a few rows. For example, if you look at the centre top of the swatch pictured above, you will see an extra column of stitches created by an accidental yarnover. In a case like this you'll never get the tension right if you just drop the extra stitch so it is best to rip back.
In the case of a wrongly crossed cable or a lace repeat that has gone askew, it may be possible to drop a few stitches down and rework them. But you need to weigh up which will be more time consuming or stressful, making this repair or ripping back and reknitting a few rows.
In these cases, rather than feeling fed up about wasted time, try and think of this as an opportunity for some more knitting, and you do like to knit, don't you? 8-)