This may be location dependent, but here in Hong Kong, preparing a business plan is useless if you are raising less than USD 5 million from angel investors (and note that angels and VC's are very different). You do a pitch deck and a 1-2 page teaser, and if someone is interested then you talk with them about business plans. Elaborate business plans are a waste of time for everyone. An angel investor is not going to want to read a stack of business plans. They want to hear a five minute pitch and if they like you, then you start talking about the details of the business. On your side, if you are spending most of your time planning and not enough time doing, then there is a problem.
Usually you can get help in creating the pitch from a local angel network. Often the network that you are pitching to will help you create the pitch. The reason people do this is that it saves time for everyone involved. For example, you'd be amazed at the number of pitches that I've seen that don't answer the question "how much money do you need?" There are some standard problems with pitches, and most of those can be resolved with a one hour conversation.
Here is the standard template that people use in HK
The standard template is intentionally designed so that you can write the pitch by yourself in a relatively short period of time.