Think essential services that will still be needed- electrician, plumber, doctor, nurse, shoe repair, etc.
In austere times folks need to make whatever they have last longer so any repair/refurbishment type businesses will still earn their daily bread.
Lead technical lightbulb replacement supervisor or executive manager of office supplies tend to be the types of positions less in demand...
It was my understanding that FerFal says repairmen and crafters actually DON'T do very well and reccomends against going that route. It is far better to be the person who supplies the parts and materials to many repairmen/craftsmen than to be the repairman. Having been "executive manager of office supplies" means you have contacts with wholesale suppliers which is a good thing. Another good position is to be the one who owns the property where people come to sell/trade goods and services.
FerFal's own words on the subject. -Blast