It depends on when I can avail them but if I invest, I'd do it before the halving happens. Just as bitcoin does, most of the altcoins are also going to move anyway after Bitcoin's reaction after the halving. If you have a better choice and you're able to buy at the same season then that's much better. You'll also DCA just as what everyone does with Bitcoin, if you are able to do so with altcoins and you should have done it before the halving for actual Bitcoin so you don't miss both ends.
In selecting alts, it is still best to invest on alts with actual use case as it will have reason to survive in the market.
Also, as much as possible, with active development and visibility from the dev team themselves.
Aside from bitcoin, there are truly worthwhile alts to look at. But should really do your own assessment on their existence.
