We have 5 steps. Step 1: Decide on the issues the agreement should cover. Step 2: Identify the interests of shareholders. Step 3: Identify shareholder value. Step 4: Identify who will make decisions - shareholders or directors. Step 5: Decide how voting power of shareholders should add up.
A shareholders' agreement also covers details about dividend payments and the distribution of earnings. Regarding the business operation, it contains provisions about the frequency of board meetings and the appointment or resignation of directors.
The biggest difference is that an SPA is the sale of all shares, and an APA is the sale of selected assets. Therefore, they are both different transactions and have different procedures.