Shop low(est) interest loan w/o ruining credit score&relationship

[Diana M.]

Hello. I'm new in the real estate world. I have been doing a lot of readings. Now one of the first things i could think of to start is getting a preapproval so i'd know how much I'd qualify. 

Now, I think It is nessesary to shop around for the lowest-interest-rate loan right? So if that is so, how do we do that:

1. Without ruining our credit rating.--> I imagine I would start with the two banks that i had been using (i use 2 banks so i will apply to both). Then people say credit unions gives great low interest so i'm thinking of going to some credit unions too. I also have some mortgage broker friends, so i am also curious as to how good of an interest rate they could give me. So am i wrong for wanting to shop around like that? Is it possible / Are there any smart ways to get the lowest interest rate that u can get without damaging ur credit score?

2. How do we shop around without creating akward relationships with the people that did our preapproval when we end up not using their preapproval (eg. It would be akward If u meet them again somewhere or in real estate networking club etc. Besides, for the business, we need to maintain good relationships with everyone right?)

Any comments or suggestions? (Feel free to say anything. No hurt feelings. :-D)

Thank you.