When I'm in an entertaining mood, I sometimes consider making my tests worth 1,000,000 points each. I wouldn't adjust anything else, I'd just make tests worth 1,000,000 points each. The way I set up my grading, test points go into their own category that amounts to a fixed 40% of a student's grade, so as long as each test is worth a similar amount, it doesn't really matter how many points I allow for each test.
Taking this a step further, though--if you use "total points" to calculate grades, you set the points for tests, quizzes, assignments, and the like in relative amounts to get the weighting you want for each category. If, additionally, you wanted to surreptitiously teach an understanding of the scale of large numbers, you might make the total points available in your class to be 1 trillion.