Online gurus give you a lot of advice. I would never consider myself a guru, but if there is one complaint I have about "gurus," it is that their advice is often one-dimensional. Advice on writing is no different. Take, for example, the instrument you use to write. For example, you may write as I am writing now, using a type of word processor--in this case the one set up by Blogger. My guess is that most writers use word processors these days. Others, however, use pen and ink or pencil. The kind of notebook varies; many writers prefer legal pads. Others may buy high school or college-ruled notebooks from a discount store. Some poets like to write on a small notebook, while screenwriters often use index cards to write their scenes. Wendell Berry uses an old manual typewriter to write his novels, poetry, and essays. A newer method is to use voice recognition software that offers speech to text and dictate their work into a word processor. I once read a short book by a writer who argued that if you want to make lots of money on books, dictate as many small books as possible, carefully edit them, and submit them to sites such as CreateSpace. Are any of these methods better than others? The right answer is "It almost always depends..."
There are two things you should think about--first, what method or methods do you prefer, and in what genres do you write. On the first point, if you only like using a word processor to write and find that works for you, then by all means use it. If you exclusively use legal pads on which to write the first draft and then revise on word processor and that works well for you, keep using them. I prefer using different methods depending on (1) my mood, and (2) the particular genre in which I am writing. For example, I use Word for most of my writing and almost exclusively for academic writing. I remember the days of writing a draft of a paper on a legal pad and then typing it up on an electric typewriter. That was time consuming, and my typewriter did not have spell check. A speller and divider I bought helped a lot, and I recommend that any writer purchase a speller and word-divider in print form in order to have it at hand when you are working on a writing project.
In writing poetry I prefer to write the first draft by printing it in pencil or ink on any piece of paper I can find available. Usually legal pads work best for me since they have sufficient room to keep me from continually dividing long lines. I revise using Word. There are times, however, that I use Word for a first draft of a poem, and sometimes that works quite well. But if a poem comes to mind in a flash, I run, grab a pencil or pen and a notebook if I have one--even a napkin if I'm at a restaurant. (A well-known poet, who shall remain unnamed, said in a talk that he wrote lots of poems on bar napkins!). I suggest you try various combinations until you find one that works for you.
Regarding screenplays, you are going to have to map out scenes or you will end up with a piece of junk.. Although there are computer programs that do that, I prefer buying a pack of 4" x 6" index cards and writing a sketch for one scene on a side of the card, using front and back so I'm sure to get every scene onto that deck. This also allows me to reorder scenes by changing the order of the cards and inserting a card if I need to write a new scene. When actually writing the screenplay, you definitely need software that formats your screenplay in the correct style. Check out free programs first; if they work well, that will save you a great deal of money. I use celtx; others prefer alternative free programs--a great list is found at http://www.scriptreaderpro.com/free-screenwriting-software/. If this does not work for you, check the many options regarding paid screenwriting software.
I prefer Word for writing novels, since I can make corrections easily using a good word processor.. There are also several writing programs; Scrivener is quite good. I have tried writing on a legal pad, but it is painfully slow to me--but many successful authors use legal pads--again, you work with what helps you keep writing, since keeping writing and not giving up often distinguishes the successful from the unsuccessful writer.
I use dictation software when I am writing autobiographical material. It is easier, for me at least, to speak about myself and have the program put it in writing. If you are in a hurry or have an upcoming deadline, and especially if you can speak clearly and quickly, then dictation may be best, though be careful to edit your work! If a written first draft is usually crap, imagine how bad a spoken first draft might be.
I hope this has been helpful to all of you who write.
