I was going to point this out too.

For those who may not know, you can put the I/O redirection anywhere in the command, not just at the end.

So you can write

    < input_file.txt grep some_pattern | grep another 

Which has the same effect as

    grep some_pattern < input_file.txt | grep another

but puts the input redirection at the beginning so you can easily follow the data flow from left to right.

I use "redirection first" in other cases such as

1>&2 echo "Error: missing file"

To make it clear up-front that I'm writing to stderr.