Being the expert that I am in this (having only played a couple games in the past year...not even with a legal list) I feel as though I can speak with some authority on the subject.
How so you may be thinking?
I play Deathwing and we've got arguably the worst "HQ" model out there right now.
It's like having a Sergeant be appointed your force Commander two minutes before making planetfall by way of drawing straws on the flight deck.
Maybe a good idea in theory, but not in reality... ever. Not when there are lots of really big, tough, mean HQs and monstrous Creatures running around out there.
So what can you do to get the most from your HQ?
1. Paint him to the best of your ability.
By that, I mean spare no expense. Make him look every bit the part. You want this guy to step onto the table a scream "Look at me everyone, I'm the one in charge."
This is going to get one of two responses from your opponent.
They are going to spend everything they have trying to kill him which in turn will spare your other units for a round or two depending on how long it takes. While this may be the right response from them if you're fielding a close combat monster, it still buys valuable time for your rank and file guys. And who knows, they may be motivated to perform better having just seen their leader drop in hail of gunfire.
Or... they are going to ignore him completely. Again, not a bad option since he can slip in and contest objectives at the last minute if you're smart about it. If he's any good, he may be able to earn his points back by getting into the fray too.
2. Model him larger than life.
We all know the tricks... big banner on his back, standing on top of a huge rock outcropping. You know the drill. He may have nothing more than a power weapon and a master crafted pistol, but he should look like he has enough firepower to bring down a medium sized battle cruiser without breaking a sweat.
This may also get one of the two previous responses from your opponent.
Make him look important and people will think he is. This guy looks important with his fancy decorated armour and really long, razor sharp claws. But he's harmless in the end. Like I said, a Sergeant that's been field promoted.
Now there is the opposite approach here that can be considered and that's to build and paint him like the rank and file guys with little or nothing to set him apart from all the other troops out there. I'm not advocating lying to your opponent, I'm saying that you just don't make your HQ stand out.
The Black Templar employ this with their Emperor's Champion on occasion. Looks like a normal troop, but no... he's taken a vow and he's much more now.
Is he a game changer, maybe not, but he'll definitely be a surprise when he starts doing all kinds of things that regular grunts aren't capable of.
3. Play your HQ in an unexpected manner.
What does that mean? If you've got a weakling, posture him on the table like he's a close combat monster. Make your opponent think your guy is much worse than he really is. Talk him up, take chances you might normally take. If you look confident in how you play him, it might be just enough for your opponent to decide it's not worth it.
While none of these are earth shattering, a combination of the three might be just what you need to extend your Commander's life past the first turn he get's out of his transport.
If you have any questions on something in this post, leave a comment and I'll be glad to answer!
Thanks goes to Chris for letting me share this post.