The most important question before raising money is what do you want to achieve with it. Raising a round just for the sake of raising a round might not be the best thing for your business. Set a goal and the resources you need, multiply by 2. This is the rule of thumb I go with, because the work you'll do will take more time than expected and you need to have a buffer on top of this. Keep in mind that raising a bigger round takes time. Make sure you have long enough runway after you've completed your goals, so you can start raising a second round if needed.