Leggy Seedlings Advice Sought

I'm no expert but I've read that putting a tin foil covered bit of card behind seedlings mean they get more light all around them and don't get so leggy. Also heard that seeding that are exposed to air movement (so those out doors) grow stronger and less leggy.. when indoors some people 'tickle' (brush lightly with fingers) seedlings to promote sturdiness. I think it makes sense  as seedlings that are exposed to movement develop sturdier as a result of having to withstand the environment.

When are you going to harden them off? It might pay to do it sooner rather than later..

I have been growing toms and other seedlings in my window sill to get them started and the first few times I tried they grew leggy so I followed advice on here and put some silver foil behind the next lot and it has helped a lot and they are now thriving.

I had big plans of making some neat surrounds but in the end I didn't even do a very good job of the silver foil but it helped a lot

Planted some french beans in 3 inch pots behind glass in south facing position,  the seedlings are now getting a touch leggy.

I presume Dwarf French, rather than Climbing? (Climbing will grow like blue-blazes, so if they are Climbing type they may just be ... climbing , rather than getting leggy.

The Dwarf type (well, like most Beans I suppose) chuck out a fairly tall stem to start with - maybe as much as 4" - so it may be mostly / just that.

But low light levels will exacerbate it, and getting them the most light you can will help. Putting them out during the day will help - the cooler / higher light conditions will make them more stocky.