Well, how lazy are you? How much money do you have? If you are rich and lazy, don’t worry about it. It doesn’t matter if you wrote that b*tch in blue crayon. As soon as you reach the end, find an editor with the time and interest to properly format and polish your manuscript. Expect to spend thousands. Editors like folks like you.
Seriously though, some editors have formatting preferences, some don’t. Ask. Some will charge you to format your manuscript properly for queries. Don’t be lazy, format it yourself. Follow standard industry guidelines even when sending your manuscript to an agent. One inch margins, double-spaced, standard black fonts (TNR, Ariel, Courier), half-inch indent for first line of your paragraphs, etc. Avoid fancy additions like drop caps, colored or script fonts, color backgrounds, etc. Stick to common file formats and avoid very old versions of word processing programs or obscure writing software that can’t convert your work into a MS Word doc, RTF, or at LEAST a TXT file. Avoid sending a PDF to an editor (unless requested). They are difficult to edit without the proper software.