The best hope to avoid a complete failure of a startup you have invested in is to stay informed and keep up-to-date on how the company is doing. A good startup CEO will send out regular communications to the investors. This should cover good news, bad news, and how the investors can help the company. If you are getting these reports, you should definitely read them, and you should have an idea of whether the company is executing well, when it is thinking about raising another round, whether the company is struggling to fill a key slot on the executive team, or failing to land key customers.
If you are not getting updates, be proactive in reaching out to the CEO or the lead investor in your financing round or other investors in the round who may be connected to the company.
Negotiating for information rights and board observer rights can be really useful, because being informed of problems early gives you the best opportunity to do something about it before the company runs out of runway.