I'm always doubtful when taking profits when altcoin rises 2x or more than that. Sometimes I'm only taking 20% from my profits before but then I knew it was smarter to sell everything. I did it once and then I was lucky to buy it back again it in a much cheaper price.
I think what you are doing is a good strategy especially when faced with a market situation which is super negative. Well, this condition is what most cryptocurrency traders fear. So we have to dare to sell at prices which are cheaper when the market is in a negative situation, so we can still make a profit even if only a little.