Loan Pre-approval process

[Jon Dang]

Bigger pockets family!

I am looking for single family rentals and I am going through the pre-approval process. 

How far in advance do yall recommend  one gets pre-approved for a morgage? I understand that all hard pulls dones within a 30 day window or so counts are a single hard pull.

I am concerned that If I get pre-approved now and my approvals expires by the time I "close" would I have get another pre-approval i.e another hard inquiry that may affect my credit score?