According to the Gellis website, the key to writing and delivering a good manuscript speech is to focus on the speech formatting and to practice delivery. These two aspects are related because a properly formatted speech will ultimately help the person deliver that speech.
The site writes that the first step of writing the speech is to focus on writing words that are suited to the manuscript speech format. In a manuscript speech, every word is meant to be spoken out loud, which is why sentences should be relatively short. Read the entire speech at the same speed level, and avoid the temptation to speed up in order to finish the speech. One key element of the manuscript speech is that the speaker looks up at the audience at the beginning and of sentences. The beginning and end of each sentence should be highlighted to remind the speaker to do this. Write all letters capitalized and have four spaces after every full stop in the speech. Indent paragraphs and place double-spacing between each word. Write the speech on loose leaf paper that is easy to turn, and only write on the top-half of each sheet. Memorize both the first paragraph and all main points, and do not forget to look at the audience in the middle of longer sentences to better connect to them.