The best way that I have found is to create a text box with no border in the margin, and type in it. Or are you talking about making comments in the margin? That would be done by using mark-ups.
page layout
Then your document ends up with whatever default margins the word processor uses. This is usually quite acceptable; personally, I rarely change those margins.
If you change margins, text that is aligned, such as centred, will stay centred within the new margins. It would be the same with left, right and justified. Adjusting the width may move some words onto different lines. So, for example, if you narrow the margins, the paragraphs will be squeezed and may move words onto the next line and make the paragraphs have more lines, but the actual alignment will not change. You can experiment and see what effect it has on your document and make whatever changes you need until you are happy with it.
look somewhere else
When you change a document's margins, you are adjusting the amount of space between the text and the edges of the page. This affects how much content fits on each page and influences the overall layout and readability of the document. Adjusting margins can also impact how printed documents look, ensuring they align properly with binding or presentation requirements.
custom margins command
changing the margins in a document areleft justification Aligins text at the left margin.centre justification Centre the line or paragraph between the margins.
If you change margins, text that is aligned, such as centred, will stay centred within the new margins. It would be the same with left, right and justified. Adjusting the width may move some words onto different lines. So, for example, if you narrow the margins, the paragraphs will be squeezed and may move words onto the next line and make the paragraphs have more lines, but the actual alignment will not change. You can experiment and see what effect it has on your document and make whatever changes you need until you are happy with it.
It should be the same on the Mac version and the Windows version of Microsoft Word. If the ruler is displayed on the top and at the side of the document window, you can use it to change your margins. Hover your mouse over the the separator between the blue area and the grey/white area of the ruler (you may need to move the indent controls out of the way first -- you can move them back later). Click and drag this either direction to change the margin. Also, if you hold down the option key, you can see the lengths between the margins (i.e. the distance from the edge of the document to the margin). If you need to adjust the margins more precisely, you can use the Document formatting dialog. It's under the menu "Format" > "Document..."
If you have Windows 2003, in a Word document, you should be able to go to "file" at the top left and click "page setup." Margins should appear at the top of the popup. For Windows 2007, you'll go to page layout at the top, and click there. "Margins" should be one of the first drop down tabs.
select page layout tabs & choose "margins".click "custom margins" to open the margins tab then in the small boxes (top,bottom,left,right and gutter)put in the measurment you need.
How to change default page margins in excel.