Some basic scam I will describe for newbie to avoid big loss. We can avoid it before attacked.
1) Wallet hacking:Basically we used some crypto wallet to store our crypto coin. Example: blockchain, coinbase, coinpayment and MyEtherwallet. We can got scam by visiting phishing site. Once you enter your details on phishing site, they will access your wallet and stole your coin.
To avoid phishing site, we can bookmark that orginal website and we should use 2FA for each site. Don't use same password your all wallet. So that we can avoid this kind of scam.
2) ICO scam: Now a days it's very difficult to avoid scam ICO. ICO become now as smart scam. They are easily make us fool. To avoid ICO scam you should research strongly about their project. Any existing project there? How quality their whitepaper? How strong team? Team are existing or fake ? Check their social media profile. How strong their community and advertising strategy? Amount of total supply etc. Even we can't avoid ICO scam, but we can minimize.
3) Ponzi scheme: Some of ICO or token offer various profit. Like lending and revenue sharing from their project. For me it's a silent scam. They scam slowly. For example : Bitconnect is one of them. I think better this kind of project.
4) Chose crypto exchange: Many people got scam for exchange his coin. Specially from local exchange. Verify difficult to identify legit local exchange. So be careful and research when you use local exchange. In the other hand some international exchange make silent scam. For example: Yobit and hitbtc. They have many bad reputation on this forum too. You can use simply search button to find them here. You have to choice best exchange for trade. Example bittrex and polonix.
5) During trade: It's the latest scam. We have no way to find out the sxmcammers. I called them big while. Because they can dump or pump any coin for a moment. Some time we can see suddenly dump or pump any coin. They have strong team. They start buy then trend become up. Once we start buy they simply sale their hold coin and market become down. Then we are worried and sale our coin even in loss.
6) Fake give away offer: May be you will received spam mail or you can see any tweet or tweeter reply with give away offer from scammer. Actually they use a name from reputation company or exchange to make fool us. Avoid this kind of massage once you see. Don't click their any link.
HYIP schemes or websites giving returns that is too good to be true. You should mention about those airdrops too, they have known to be used for scamming in the past.
I will edit post if I found more new scam system.