i swear to god, i read many of your posts and think you must be as anal retentive as me!
i had a nice canon printer that i could print 3x5 index cards on. i used to make flashcards that way. first, i open up a word document. click on "file", "page setup" and the "margins" tab. you will set all your "top", "bottom", "left" and "right" margins so that what you have left on your word document is the area of an index card that you will be printing on. make sure your "top" and "left" margins are as narrow as your printer is going to allow you to make them. with all that set in place, run a test. type some stuff in the field that is left on the word document. stick a blank piece of paper in your printer and see how it prints out. place a blank index card on top (or behind it) matching the top left corners and see if it's going to fill your index card adequately. if so, try printing an index card. place the card in the printer, slide that bar that holds the paper in place all the way over to wedge the card in position and hit "print" to see what happens. you may have to play around with this a bit to get it all exactly as you want it and to accommodate your printer. once it is all worked out, clear the text from the word document and "save" this document as a template for printing index cards so you don't have to do all this work over.
as you can see, it takes some playing around to get a document formatted to work for you. i am actually able to make a table without any printed gridlines. some of the newer word programs won't let you do this. by selecting no gridlines for a table i eliminate all the malarkey of fiddling around with the border lines. the table program allows me to see the gridlines on the computer so i can see the edges of each cell, but doesn't print them. i can then print all the information i want on an index card inside the cell of this table and then print it. there is still the problem of the top and left margin defaults on the printer though. to me, those half-inch borders that my computer won't print out are a waste of my paper.
i have dealt with the top and left margin default issue by creating a one column, one row table centered in the middle of a document. i will print out one sheet of paper with the borders (that can be done on the tables and borders toolbar by coloring the edges of the cell before printing) so i know where they are. then, undo the colored edges of the cell after printing the sheet of paper). i will carefully scotch tape an index card (or put a post-it note) inside this printed border on the sheet of paper and run it through the printer to get what i wanted printed on the index card or post-it note. i just keep re-using this one sheet of paper for each index card or post-it note because nothing else prints on it anyway. i have all kinds of printed post-it notes in my icd-9-cm code book that i've done this way. all because i'm anal retentive and like things to look nice and organized.
you can customize the size of index cards by using card stock that you can get from office supply stores. when i just needed two 4x6 index cards for one of my math classes (legal cheat sheets for a geometry test), that is how i created them. table and two sheet of white card stock. i had stuff bold-face, colored, and underlined on these cards in the smallest font that i could read them! i set the table to print very light gray borders so i knew where to cut them out with my scissors.
i hope my explanations make sense. ask me if you need it explained better. i do this stuff all the time, so i may have left something out without realizing it.