Since you're meeting VCs, I will assume you're raising money.

1.) Properly communicate how much money you are raising and why. Understand how much money they normally invest in a startup (don't ask for $5k from someone that normally invests $100k). Figure out how much money you need to operate for 12-18 months or more. This should be primarily based on expected team size & team growth. $10k per head per month is a good estimate (on the low end). A team of six needs approximately $750k for a year.

2.) Focus on the team if you're seed stage

3.) Have a prototype of what you're building

4.) Understand your market well