Running largest to largest will produce an intermediate gear. For the lowest gear you want smallest pulling the largest. The basic math for gear ratios is driving sprocket divided by driven sprocket, so either a larger chainring or a smaller rear sprocket will have a similar effect.

While it's absolutely critical that the chain can loop the two largest sprockets with an inch to spare (so as not to destroy the drive if you accidentally shift into it) it's not generally a good idea to use the combination much. The crossing angle inner to outer (or the opposite small/small combination) causes increased friction and wear, and a more efficient comparable ratio probably exists with a more efficient combination.

If you have a few minutes to spare you can count the teeth in each sprocket front and rear, and do the math for the ratio of each combination to determine the best combinations that will give you a good selection of gears without needing use the inefficient crossed pairs.