Scarra has posted a great cheat sheet explaining the Economy vs Reroll strategy for TFT.

There are two basic strategies in Teamfight Tactics that affect the decisions you make as you play.  

The Economy strategy saves money to create interest, but has a very short bench and less flexibility.  You get 2-star and 3-star champions later, but you have more money for rerolls to build out your squad the way that you want to. 

The Reroll strategy involves getting a larger bench of 1-star champions early and using your early money to reroll those into 2-star and 3-star champions early.   

Remembering that win and loss streaks also give money you have to balance your early game (and taking health from your opponents) versus the long term game of having the strongest squad.   

Which strategy do you emply the most?

You can visit Scarra's Twitch Channel to watch him play.   He's a strong player.