There's a lot to learn from sales organizations on how to make clean, simple decisions at any level. To explain:

Sales teams are built simply - they've got revenue goals, a process to hit them, and the best team to execute on the process. It's all, as one of my managers used to put it, "laws of physics". Startup founders can apply these laws of physics to practically any function, and even the entire company.

The powerful structure sales teams worldwide use? Quarterly goals (or 3-month goals). 

Seems trivial, until you think of how few non-sales teams have clean, specific, detailed quarterly goals. While there are many right answers, let me call out the thumb rule here for running a startup:

When faced with a tactical decision, simple look at one metric: Three-month impact. And take the decision that gives you the best outcome based on your next 3 months. The idea here is to consciously keep any other biases out.

 Examples:

• If you're deciding whether to buy a ping pong table for the office, simply think about whether it'll help you hit your 3-month team-building/collaboration goal (Don't have one? Maybe that's a problem)
• If you're deciding whether to buy some market research, simply check on whether it will bring in additional revenue in the next 3 months. If not, drop it.
• If you're deciding whether to hire someone, simply think through 3 month impact. The best hires bring initial results within 3 months, easily.

Secret: Defer a decision until you're sure there's a 3 month impact.

P.S: I had used variants of this myself, but those crystallized into this thumb rule after chatting with a friend on the topic (Check out his company Meesho, they're funded by Y Combinator)