Before a Procedure Call

    addi $sp, $sp, -4 * number of caller saved registers

Save in-use registers (we may not have any to save):

    sw   $t0, 0($sp)
    sw   $t1, 4($sp)
    ...

Grow the stack to pass arguments (if any):

    addi $sp, $sp, -4 * number of arguments

Put the arguments on the stack:

    sw   ..., 0($sp)  # First argument
    sw   ..., 4($sp)  # Second argument
    ...

Jump to the function (puts the return address into $ra):

    jal  functionLabel

To summarize:

    addi $sp, $sp, -4 * number of caller saved registers
    sw   $t0, 0($sp)
    sw   $t1, 4($sp)
    ...
    addi $sp, $sp, -4 * number of arguments
    sw   ..., 0($sp)  # First argument
    sw   ..., 4($sp)  # Second argument
    ...
    jal  functionLabel