I'm not sure exactly how current measures could be strengthened but I can think of a few very easy wins:
Stop click and collect of any old retail: My husband works in non essential retail. They are as busy as ever with an almost full team in place as customers are shopping via click and collect. Non of the items are remotely essential. How can the government on one hand tell us we should leave home only for a few reasons, but then make click and collect of any non essential retail items allowed?
Discourage visors: So many people are wearing visors instead of masks. In my local butchers and hairdressers all staff wear visors only. They think this is as effective as a mask. I accept that for some people it is all that they can tolerate, but that is not what is happening in many cases. This needs to be more widely publicised.
Ventilation: many many places aren't keeping doors open. I know it is cold but this has been proven to make an enormous difference. My local garage, post office, corner shop, chemist all have no windows and keep the door closed. I don't think this is an informed decision- they just don't know what a huge difference natural ventilation can make.
Register bubbles: ask people to register their bubble details online to help stop those abusing the system and having multiple bubbles.
Push home working: in lockdown one I had 15 customers who began to wfh for the first time ever. 13 of these have now gone back to their workplace- they all tell me they could work perfectly well from home but their employers want them back in the workplace.
Provide higher grade masks for some vital workers who are constantly at risk e.g. bus drivers, bin men (all together in one cab), driving instructors, care workers etc.. In fact I can't understand why these are still in such short supply, surely since March we could have ramped up production so they were more readily available?