how to choose the best Shipping rates in USA?

[AbybestGift2345]

I'm starting new online shop for  Personalized products such as t.shirts , mugs, tumbler ....

I want to setup the good shipping rates in USA only right now 

Do I choose by weight or flat rates ?

I'll ship with USPS.

[Mirdas]

Hi @AbybestGift2345 ,

You can use discounted USPS shipping rates, which are available with Shopify Shipping. You can also try the USPS rates at checkout as well.