Comma Splices

There's always one place my grammar tips for the year have to begin...and that's with the comma splice.

While gazing into infinity, take a look at this sentence:
Han Solo shot first, Greedo never saw it coming.

Are you trembling with grammar indignation? Because I am! Han's suave survival skills are marred by a comma splice.

What is a comma splice?
A comma splice combines two complete sentences into one sentence. It's one of the most common grammar errors around, but it's also one of the easiest to fix.

How do you spot a comma splice?
Sentences can be made up of many parts, but a complete sentence requires only 3 things: a subject, a verb, and a complete idea. Such a thing may occur with only 2 words, and still be a complete sentence: Han ran.

If you've combined 2 complete sentences with a comma, scrutinize it to make sure you haven't spliced. If both sentences are, indeed, complete, and you haven't included a coordinating conjunction (FANBOYS: for, and, nor, but, or, yet, so), then you may have committed a comma splice.

Han ran from the bounty hunter, Leia saved the day. (Eek!)

Han ran from the bounty, so Leia saved the day. (Yay!)

Fix it, fix it, fix it!
Quickest route:
Exchange that comma for a period (full stop).

Han shot first. Greedo never saw it coming.

Other options:
If you want your sentences linked, consider a coordinating conjunction (FANBOYS), or a semi-colon (which should be used sparingly!).

Han shot first, and Greedo never saw it coming. 

Leia rescued Han from Jabba the Hut; she disguised herself has a bounty hunter. (She's awesome!)