How do you detect a scam site?

Here, while we are working online usually we face scam sites. I use following strategies to find them out.
1) I check the site on scam advisor.
2) Then on second phase I check on trust piolet.
3) I looked at it's payout thershold, if it is more then $50 and the site is not famous then I keep myself away.
4) I try to see something unusual in it, like click one ad and earn $.1
Or earn daily $50, or invest then can start work.

The best way to avoid getting scammed is to work only on those sites that have established trust through many years

I usually search the feedback online and then, check any proof of payments on Google. I random do this though.

What I usually do is, browse through forums to find out which ones are legitimate. In addition, I make it a point to look for payment proofs.