This is the biggest mistake we have ever made.

The biggest mistake that I see out of state investors make is unnowingly buying in the wrong neighborhoods and buying the wrong asset class.

It's a dual weapon.There's even a big net cap/cash flow poster on here that's more or less walked into this debate and admitted not holding was a mistake.

Although its not the same as starting a syndication it can be at a lot smaller scale which can be more forgiving for mistakes.

@Ankush R.Recommend exploring as many sources as possible to get referrals AND cross-reference them to get as much accurate information as possible.Check out NARPM.com, BP’s Property Manager Finder (BiggerPockets: The Real Estate Investing Social Network), etc.Also, encourage you to learn from the mistakes of others - by reading posts here on BiggerPockets about owners not having their expectations met by their current Property Management Company.

I'm looking to avoid rookie pitfalls/mistakes/regrets.

This is a mistake a lot of new investors fall into. 

Working with them is the biggest mistake of my real estate journey.

If you try it on your own, one small mistake can set you back to square one.

This is a very common mistake that investors make and it will cut into your rent and days on market by a lot.