A good suggestions and that is also go down to buying as lowest price as possible. I think most of the altcoins that do very well in 2017 are now undervalued now and it will not be bad if you can invest in them now. In some months to come some of them are really going to recover and by then, you will be able to sell them at profits.
now we can see some altcoins rising. bitcoin doesn't seem to move very fast, hopefully the dominance of bitcoin has dropped, and now altcoin will start the pump. we have to see some altcoin movements again, starting from ethereum which slowly rises.