Legal agreements people feel that bring in conditions and hamper relationships but in reality it is not it helps in facilitating who is going to what and who is going to be responsible for what.
This is the biggest flaw in startups, which leads to breaking and killing of startup when things change.
While starting the legal agreements important are getting it registered as pvt ltd and having clarity that who are directors of the company and what share they hold in the company is very essential.
The same implies when you are getting your clients on board have clarity on what is the deliverable and when needs to be delivered have complete documentation of the process as this helps when things go wrong.
As you are dealing with human beings who are always are subjected to change for simple example you started a designing agency and got a client for designing the logo.
If proper documentation is not done then the client starts asking for more and more designs and you start feeling frustrated because you had not mentioned in the agreement on how many variations of logo will be given for the price he is paying.
The same is when you are getting involved into making or receiving payments, be clear at the start which will ensure that you end up happily and not fighting for payments and spending time on follow ups which eat up your margins.
Even when you are hiring people though its start up have proper documentation in place give the employee a proper offer letter and appointment letter and when he leaves get his resignation letter and knowledge transfer no matter even if he is your best of best friend.