How to report income? I received PayPal and wire transfers of consulting income from businesses in India--no paper trail, no 1099 or other tax forms.

How do I report income from companies that do not provide any IRS or other reporting forms such as 1099?

I received PayPal and wire transfers of consulting income from businesses in India.  These companies provide no paper trail, no 1099 or other tax forms.  So how do I enter these sources of income including three checks of $300 each from trainees?