Hello. I have been installing floors for over 21 years and have always used a chalk-line grid pattern, as do most installers. This allows me to see where every tile is going before I begin. I can then make all of the perimeter cuts first. The important thing is the grid is very acturate and perfectly square. If I have a 12 or 13 inch tile I go with 4 tiles per grid square. If it is 16 inch or larger I go with 1 tile per grid square.
If you feel more comfortable using spacers then by all means, do so, but you will need at least two chalk lines that cross each other (perpendicular) to begin your layout. By the way, make sure you remove the spacers prior to grouting. I have seen jobs where the installers left the spacers and grouted over. The grout then pops out in every corner!
