Played 7 wonders a few times this weekend. It's fun...and so, so fast. I still have no idea what I'm doing. The game seems highly luck-based. But, I'll learn more as wenplay more. I could be way off base. It feels like a mix of citadels and race for the galaxy.
I don't think it's that luckbased. At least, I seem to win more often than pure chance allows.
It's about optimizing, but for this you need to be able to collect and process a lot of information.
What resources are available to me through my own board/cards, my neighbor's boards/cards?
Which strategies are they following? Do they play mostly blue, green, red or yellow cards?
I find that I win a lot of the games, because I'm doing something differently than the other players or at least my neighbors. There's no use fighting a war of attrition with red cards, this will make sure you both lose.
If you play just with 3 players, it's easier to manipulate the hands and deny good stuff from your opponents. With 7 players you just have to focus on scoring as much as you can.
Be versatile for as long as you can. Don't overcommit to a strategy and find out at the end that the one card you needed is underneath a player's wonder. Green cards are good, but they're the biggest gamble. See if you can get at least 3 different ones, so you'll score 10 points and get to build some free stuff.