Always hold majority of your fund in btc rather than altcoin as btc is dominant one and other follow its trend so if there will be rally then sure btc will ride but when it reaches certain point altcoin will follow it. So my best advice is to make 70:30 or 80:20 btc to altcoin ratio to get safe ride in having duration.
This is a good advise if we are investing a decent amount, however, for people who aim high enough and does not have a decent amount of investment, this won't work for them as they might be bored holding too long not making much.
the formula I follow is risk high on altcoins when the capital is small, but always do due diligence when investing.