The 'interactive fiction' format hasn't changed in any fundamental way since the early 1970s, in the same way that the format of the novel hasn't since 1700.

If you're setting a game during the Cuban Missile Crisis, look through a library. find out what people were wearing, what other issues were in the news, how houses were furnished, what cars were being driven. Especially include things which now seem foreign.

This means keeping many trails open at once, inevitably requiring a fairly 'parallel' plot. This plot should be discovered rather than announced, so show, don't tell.

I don't really believe in 'directions' in art; the rope twists as you follow it, that's all.

The time has mainly gone on getting Inform into a decent shape for public use. I suppose the plot of 'Curses' makes a sequel conceivable when compared with, say, the plot of 'Hamlet' but none is planned.

I try to make puzzles range all the way from easy to hard, and to leave many open at once.

I like to employ a form of repetition, in which the same elements recur but in different and unexpected ways. rather than being discarded as soon as they are understood or passed over.