If your playing seriously, like return said, have an alliance ready. Its always good to organize before a round, and have a plan.
And you should also have energy, lots of it. Scans become very important the first 100 ticks.
And its not bad to join late! My best round was when i joined at tick 340, ended it ranked 20, 29 crystals, 800 units, and a relic

(until i lost it xD)