Hello guys, having been here for a while now, I feel that having a higher percentage of your portfolio on bitcoin and maybe the rest 30 or 35% on already good and established altcoins like ETH, BCH, Stellar, brave. BNB, Vchain, etc, is a good way of staying away from useless projects. I have come to an understanding that running after new promising projects always leave you heartbroken in 97times, and running after IEO to quickly make up for past losses lead to more havoc on your fund. So stick to the safe zone.
Lol youre not the only one that has had this experience 
I have had this same experience, maybe its due to me making a mistake or something. But I know for sure that I did proper research on those projects that I invested but most of them still disappointed. Thats why I have made up my mind to keep investing in altcoins that are also well established. And I was go for the top ten or twenty coins, I no longer go below that because those other ones tends to be disappointing. For now I have up to six altcoins that are stored in my wallet: Ethereum, Ox, Bitcoin Cash, Litecoin, Stellar Lumens, and BAT. Theres been a hype around Chainlink this year and I might add it to portfolio. I have done research on it and its good.