Easily the best way to avoid pitfalls is to network with other writers. This can be done on-line or by joining writers groups and attending conferences, courses and workshops. Writing is a lonely business and it is easy to become locked in ones own work. Discussing your writing with others can help you think objectively about the project you are working on and generate much needed support. Without the support of others it is easy to become discouraged and may lead you to give up.
Asking three to five writers, not closely related to you to critique your work is very beneficial. If more than two are critical about a particular point then it probably means it should either be radically altered or deleted altogether. But remember you are the final arbiter. It is your work so it is up to you in the end.
Employing a professional editor helps improve quality although this will cost money. There are many good ones about. They advertise in the writing press but it is always best to seek recommendations from fellow writers. Find one who you are happy to work with and who is sympathetic to your style.
Do not order books until you are happy with the proofs and do not order more than 20 books at a time or until you are sure you have a market for them. It is easy for the most diligent proof reader to miss an error which will be picked up by readers of your first print run. Many a self publisher has ended up with a stack of books riddled with a glaring error which inhibits their sale.
Start at the last page when editing and read your manuscript back to front. Have your computer read your manuscript to you out-loud. There are computer programs which offer a text-to-speech feature. Some are free. Use search engines such as Google to find them. Your book may sound like Stephen Hawking is reading it, some of the contractions sound weird but, as you read along with the voice, you will notice some errors that your eyes alone would have missed.
Wait until you have three completed books before self publishing with your own company and look to utilising different formats. Link to other Self Publishers websites and online social networks to market each others books and so become a bigger fish in a smaller pool. Pitch your book in 15 minutes. Produce a profit and loss publication plan.
By employing some or all of these tips you ought to achieve your ultimate aim which should be to publish your own work that you and others will enjoy at a cost which you can afford.