1. Obtain a hospital experience.
An experience of at least 1 year is alright. It doesn't matter if you're a generalist (rotated in different sections in the lab) or a specialist as long as you get exposure in a hospital setting. American employers need to know if you have performed complex tests and can operate machines.
2. Take certification exams like ASCP or AMT
As for me, I took the ASCP since most of my workmates took the same but I think taking ASCP is more advantageous as it is recognized internationally. It is accepted by countries that has their own certifying exams like middle east. Meaning, you need not to take HAAD if you already passed ASCP.
To know more about my ASCP experience, click this link.
3. Take English proficiency exams
It can be IELTS or TOEFL. The purpose of taking these exams is not just to gauge your english fluency and comprehension but it is a prerequisite to get VisaScreen. To pass IELTS, the target band score is at least 7.0 with speaking score of 7.0 and above. This is the passing score to get qualified for USA.
To know about my IELTS experience, click this link
4. Have your Transcript of Records evaluated
You can choose either Josef Silny and Associates or WES. They will evaluate your college transcripts and see of the curriculum matches that of an American MT curriculum.
4. Process your VisaScreen
VisaScreen is a certificate that recognizes that you are eligible to work as a healthcare professional. It took me 3 months to process all of it before they FedExed my certificate.
After that you may now start your search of an employer thru browsing the internet or asking assistance from an agent.