At the moment, it's a little annoying that parameters can't be formatted properly if the form of the parameter in reminder text is different to how it should look next to the keyword. For example, Demonic Collusion has parameter "Discard two cards" (capital D) but in the reminder text it's lower case, "You may discard two cards..." (little D).
­Dromoka's Gift has parameter "4" (numeric) but reminder text "put four +1/+1 counters on it" (words).

I'm thinking if a mechanic has parameters associated, I could provide options in reminder text something like

> You may \lower1 in addition to any other costs as you cast this spell...

> You may sacrifice \word1 creatures

Other options could be

> {1,lower} and {1,words}

It's all rather UNIX-y, intimidating, unintuitive though. What would be more approachable?

> [Parameter 1], [Parameter 1 in lower case], [Parameter 1 in words]

> You may [Parameter 1 in lower case] in addition to any other costs as you cast this spell
> You may sacrifice [Parameter 1 in words] creatures

Yeah, that seems nicer.