Getting Visa after been in Hong Kong to enter in China once

Nelson, do you stay in your home country now? If yes, you should apply for it from the embassy in your country. It's not recommended to apply from HK, since it now becomes difficult. If you apply from your country, you just need to submit the application documents and then wait for the result. The documents include your passport, a photocopy of the passport's data page, a fully completed application form, a recent bare-headed photo against white backgound, round-trip tickets and hotel booking orders.