Use rubrics. Conduct a class discussion in which students develop a rubric to be used for scoring performance tasks. This allows students to gain an understanding of expectations for solutions to multi-step problems.

Use notebook/homework quizzes as a way to easily assess if students are doing their homework. Provide students with a list of 10 homework problems to copy from their notebook (no textbooks) and you grade these problems. This also allows student more time to do homework if they get something they don't understand.

Create macros in a spreadsheet to make grading easier. Download example (XLS)  

Avoid all-or-nothing grading schemes. Insist on fully detailed explanations whenever your students solve problems, and reward reasonable efforts with partial credit. This encourages students to value the process of solving a problem as much as the product of obtaining a correct answer.

Uses pluses, not minuses. Use positively oriented credit accumulation; that is, use "+2 out of 4 points" rather than "-2 out of 4 points."

Test yourself. You should be able to complete a test in a quarter of the time that your students will have.

Be careful of "indiscriminate zeroes." Say a student averages 96 on five assignments. Then fails to turn in a sixth assignment and is given a zero her homework average plummets to 80. This makes a student who normally does A-level work look like a C student.