Larger tile generally has less grout. I would pick out one that could accommodate all of the areas. Take a look at tile spaces in the photo section of Houzz for ideas. This has multiple sized pieces for a patterned look: This might be too big, but tile in different sizes might work: and

These are attractive options: and

What size areas are you tiling?

about a 5ft x 3ft area

That's a small area, I would jazz it up with a smaller size tile under 8". You can spend a little more on an area that size.

even 12 x 18 sized tiles for a more contemporary feel.