Do you want to grow the dollar value of your ETH or grow the amount of ETH? If you want to grow the dollar value, you can easily do so by holding on to ETH. Once market recover, you should be able to see ETH price increase and hence the dollar value is higher than now.
If you want to grow ETH, you can use it to invest in promising ICO project or altcoin. However you have to do good research to find the next X10 or X100 project.
Actually, I don't think for holding now. I expect to try for grow my ETH.
Someone saying, ICO not good right now, So I am afraid about ICO.
There are options to increase that amount as trading and ICO investing. But as a newcomer, you should not try with these. Holding your eth is the best way for you. It is the most secure way. But if you like you can invest a part of it for a promising alts like Neo or waves.
One of my friend told me for waves hodl. He also said that, Trx coin a promising coin also. If you want please hold "Waves & Trx".
Noiw I am thinking about this. Maybe it will better than ICO invest.