This is not a fully planned structure, I do not work in education and have little theoretical knowledge of how to impart education to others, so this is really no more than musings.
The school/ further education systems appears to have difficulties as one size does not fit all. Some pupils wish to follow a more academic pathway, and society, expectations etc has pushed a far greater proportion down the school-university path, for some I believe this does not play to either their strengths or what they possibly ultimately want.
With this in mind I would consider trying to construct an education system that was far more integrated in its ability to deliver both academic and vocational paths.
Attempts to deliver vocational education have in the past involved pupils leaving their schools at say 16 to step on to this different pathway to vocational training, I would prefer to see a system where they could, to a degree, pursue both academic and vocational pathways at the same time, without requiring to move institution leaving their friends, staff who know them etc. I would also wish to see options for vocational training available far earlier, say at fourteen, there are a number of pupils whose education between the ages of 14-16 just does not deliver, if they have little interest in school during this age band it can be difficult to reignite motivation later.
So, how to deliver.
Not all schools can deliver all subjects, the requirements of space, teaching and resources makes this a mere utopian dream re unlimited choice. But certainly in urban areas the idea of grouping schools in clusters where each delivers core subjects and each also has their niche areas of expertise appeals.
Timetabling could be arranged that certain days were for delivery of core subjects, all pupils would take these, my list would cover English, Arithmetic , PE, possibly basic maths (to be considered) etc. The pupils attend their main school on these days. On the other days the option subjects would be delivered and within these I would wish to see far more vocational subjects e.g. car mechanics, joinery, hairdressing, office admin and so on. Children then attend whichever cluster school/ schools offers that option.
To take the example re car mechanics, this would be delivered via a joint workshop approach and appropriate lessons. So say electrical fault tracking would cover some of the topics currently covered in physics re electrical circuits, all the W=VI, V=IR etc are required, but taught in a real life situation using meters, test lamps etc. This can at a more advanced stage extend to computer diagnostics.
The key advantages I see are:
Pupils get to try before they buy, so to speak. There is scope to switch to another skill if the experience does not match the expectation.
Other subjects are integrated within the practical subjects.
Pupils who develop at different rates have the ability to continue to learn academic subjects at the same time, integrated switching is simpler.
Pupils get to stay, at least in part, with their school friends/ staff who know them.
The schools delivering the niche offerings can establish close links with local FE colleges and Universities re their niche, possibly with guest staff coming into the schools etc. Links with local employers can also be arranged.
The school system does not have the divisive issue re the old two stream- grammar/ secondary modern, pupils remain within the cluster and can therefore change the pathway they are following .
Now I appreciate this needs more thought, there are no doubt a number of holes and provision in rural areas may , due to limited number of local schools, mean choices are restricted, but it would mean that skilled trades/technicians numbers might possibly increase .
How you would fit the courses into a qualification framework I have no real ideas, however unless something is done to better integrate schools/ FE/Universities, and dispel the quasi us and them divides, pupils will continue to make education choices for the wrong reasons.