Struggling with position sizing on altcoins — how do you manage?

I'm still relatively new to the crypto space, especially beyond $BTC and $ETH. When I'm looking at some of the smaller cap altcoins, the volatility is just insane compared to the majors. I'm finding it hard to get a handle on what a sensible position size looks like without feeling like I'm either overexposed or missing out. For those of you who've been around a while, how do you adjust your risk sizing for these more volatile assets?