There's a misconception in the world of law that you need a bunch of complex conjunctions like 'heretofores,' etc. There's no rule stating that you need to use a weird dictionary to make your contract viable. You can keep the contract simple and draft it in easy English without unnecessarily overcomplicating it with difficult words.
Always specify who pays whom in the contract when the payments must be made. Also, add the conditions for making payments. As money is always the main issue, it should be very detailed. Put the method of your payment in the contract as well. If you are going to pay in installments or only when the work is completed, then say so with date, time, and requirements.
If all the parties in the contract are from different states, then you should choose only one of your state's laws to avoid sticky legal wrangling later. Also, you should include where you will arbitrate, mediate, or bring legal actions under contract. This way, it will be easier to solve any disputes.
Identifying the party correctly sounds like an obvious thing but you will be surprised by how often businesses get this wrong. You need to include the correct legal name of the companies as they will be liable for all the actions and they are obligated under the agreement to perform the terms in the contract. This also includes who you have legal rights against in case things went south or if there are any complications. For example, if a business is organized as a corporation or LLC, address it by its legal name - which includes LLC or Inc. suffix.
A contract is between two people or businesses and like every relationship in the world, this can end too. So, it makes sense to set out the circumstances under which the pirates can terminate the contract. For example, if one side misses many major deadlines, the other party should have the right to terminate the contract legally.
The body of the agreement contract should mention the rights and obligations of each party in detail. If you have discussed something verbally, then it is necessary to add it in a written agreement, otherwise, it is not considered. Most of the judges in the contract law only consider written contracts as true. So, include everything that is crucial for both parties. If you forgot to add something in the initial agreement, you can create a short amendment and ask the other party to read and sign it for it to become a part of the contract.
Disputes are common between businesses and people. Always include this part in the written agreement. What will you or the other party do if things go wrong? You can write in the contract that you will solve the dispute through mediation or arbitration instead of going to court to save some time and money.