Here's the combination I personally look for to avoid scams before even submitting a proposal, and avoid wasting 'connects':
1. Payment method verified
2. Client has been active on Upwork over 3 months at least, but over 1 year preferred ("Member Since" date in their profile)
3. Total money spent by client over $1k (I give some lee-way to this if the client appears to be an individual or very small company that has hired for multiple 'tiny' contracts on UW)
4. The client has hired at least 3 other freelancers dating back at least 1 month in the past, and their hire history shows they have been paying those freelancers ("Billed: $xxx.xx", etc) when you look at their previous/past hires.
5. 4-5 star reviews (cumulative) from freelancers or at least no geniune complaints from freelancers posted in their 'reviews' (like "Client was disrespectful", "Dude refused to pay", etc.). If they have on-going contracts, they might not have reviews yet, but they should at least have few or no complaints
6. I open some of the past and 'current' jobs they have posted and verify they look like real, legal, legitimate jobs
7. I then open some of the freelancer profiles of people they have 'hired' before to verify they appear to be real, legitimate freelancers with favorable reputations. (A 'client' that has hired nothing but 'sketchy' freelancers is usually running a scam that involves those fake(?) freelancer profiles)
8. I look at the LOCATION they claim to be in versus the "timezone" or current time showing on their profile. If somebody has a "current time" that doesn't make sense for the location they claim to be in, I leave it alone. I'm not talking off by 1-2 time zones due to travel, but somebody claiming to be in the U.S. and having a 'time zone' that couldn't possibly be anywhere in the U.S. on their profile. If they are lying about their location, then what else are they lying about?
9. I look at their "hire rate" on the profile. If they've posted multiple jobs and have a 0% hire rate or a very low one, I don't bother.
10. Look at the job post itself: If they've already 'hired' many other people for the same job or are 'inviting' and 'interviewing' a large quantity of people for the same job, it's usually a scam where they are 'hiring' anybody that applies or a waste of connects (because your proposal may never been seen). If they have multiple jobs posted with essentially the same title as the one you are viewing, avoid it.
Basically, I simply don't deal with brand 'new' clients ever or clients with no reputation/track-record or a bad reputation because I have found the vast majority to be scams or people that aren't serious prospects.
Upwork doesn't officially 'discourage' people from approaching brand new clients, but it's my personal policy that I have found works well for me because I have never been scammed on UW.
I also apply this same criteria to 'invites' I receive. If they don't meet my criteria, it gets rejected: Don't dare send me an 'invite' if you've just joined the platform 1 day ago or "today", have no hires, no money spent, and worst of all, don't even have a payment method on file. It gets rejected faster than Shaq can block a lay-up on a basketball court. lol I don't have time for the non-sense.
It might mean missing out on some viable 'leads', but that's a risk I'm willing to take to avoid being scammed. Examining everything available on the job post about the client's history, who they've hired, and what they've paid and being very selective about who you spend 'connects' on or which 'invites' you respond to goes a long way in avoiding the scams.
