Tbh I'm referring to those who, rightly or wrongly, just want to do the bare minimum to try and accrue money for the future and accept investments will go up and down.
You suggested a S & S ISA, is that what you meant, or ISAS in general? Either way, fair comment, but with reservations on the S&S version.
Once you're in a position to have more than a few thousand in the bank, the year end counts.
You can have a lifetime isa , which I haven't mentioned. They're for up to 39 year olds and iirc only a max of £1k pa.
You can put money into an isa every month as long as it's within the limits, but you have to put some brain input into where it's going. Bowler Hattist might say the FTSE is a fine proper place, but you'd have made bugger all (one and a bit percent) last year when a different but unremarkable choice would have yielded 20. You'd have been better off in that case, with a cash ISA, as long as you kept track of their rates, because they tend to turn to as little as the bank or whatever can get away with wthout incurring the wrath of the press.
Cash Isas operated that way are little better than the worthy
in a region that is politically stable and has a large, well-regulated market FTSE, which like most stock based options, can go negative or underporform what migh be called a slightly intelligent strategy.
Unfortunately, as far as I'm aware, there aren't simple places to put or add to a fund which is managed with that slight ntelligence, for you. By overall, I mean do some moving about, including into cash when appropriate.
There are managed funds, but they're all pretty narrow and ultra cautious, and also go negative.
In the medium (months/years) term, some sectors do better than others. technology is the obvious one. Sooner or later they pause, like the tech one is starting to do, so other sectors appeal.
India, derided above, had been doing very well for long enough for it to be a decent ploy for months at least. It has risen 25% in the 6 months since I chose it.
Glocal tech is also up 25%, and Japan 30%.
If they slow down or drop they'll be sold or switched.
The past year: Ignore the yellow one, the three mentioned are the India/Tech/Japan, FTSE is the blue one
By next year, large companies in China are forecast to make an appearance.