Here's what we do:
Write a cover letter detailing the types of hardship incurred: family separation, financial, medical, etc. Evaluate whether the hardship is "extreme" citing relevant court and AAO decisions. Then, attach 10-20 exhibits all marked with tabs.
We put the I-601 form directly under the cover letter and the exhibits following the I-601. We use a two-hole punch and an acco-fastener to keep everything together.
For additional information, please see
it's really not rocket science, thankfully.
Write a cover letter detailing the hardship and attach document marked as exhibits.