While spelling errors can be written off as typos, grammar errors will just plain make you and your brand look dumb.  No, really.  It needs to be said.  Dumb.

The most common, DEAR-GOD-PLEASE-MAKE-IT-STOP grammatical errors you can fix in two shakes of a lamb’s tail:

1.) YOUR & YOU’RE

Ask yourself: does someone own what you’re describing?  Then it’s a ‘your’:

your books, your shoes, your love, your thankfulness, your dirty laundry, your umbrella

If no one owns what you’re describing and the words ‘you are’ could replace it in a sentence, it’s a ‘you’re’ you’ll be needing:

you’re awesome, you’re a pal, you’re going to the fair, you’re silly, you’re super

Again: ‘your’ indicates possession, ‘you’re’ is a contraction standing for ‘you are.’

2.) THEIR & THEY’RE

Just like our previous example, ‘their’ indicates possession:

their shoes, their party, their website, their company, their toilet paper

If no one owns what you’re describing, ‘they’re’ stands in for ‘they are’:

they’re nifty, they’re mean, they’re quite a pair

Again: ‘their’ indicates possession, ‘they’re’ is a contraction standing in for ‘they are.’

I saw your eyes glazing over, so I’ll stop there for now.  But, if your grammatical brain is suddenly wishing for more ways to self-correct, I would hit up Grammar Girl’s Quick and Dirty Tips. Grammar Girl rocks.