If you were a self-employed individual working abroad, you would still report your self-employment earnings and expenses on Schedule C (Form 1040) Profit or Loss From Business.
If you need to remove the self-employment tax due to a Social Security agreement with the country in which you worked, please see Schedule SE - Expatriate Social Security Agreement for additional information.
Note that any link in the information above is updated each year automatically and will take you to the most recent version of the document at the time it is accessed.