I think there are several things that can be done if the Government would support them:
Train more doctors and give them bursaries to cover fees on the basis that they take up UK positions for 5 years. No restrictions on training numbers either!
Nurses should also get free training in return for working in UK.
Complete overhaul of the prescription system. It is crazy that doctors have to sign repeats every month. Roll out a patient app that allows repeat requests online instead of the ridiculous paper system now in place. Pharmacies often do meds reviews - this could be more extensive to relieve doctors.
Walk-in clinics so no appointment necessary. Nurses (not admin staff) to triage and help those that don't actually need a doctor. This could also take a lot of non-urgent care away from A&E. Charge a small fee to be seen to deter time-wasters.
More specialists working within walk-in clinics - eg. mental health, dermatology, diabetes care, menopause, gynaecology, etc. E.g. come on a Monday afternoon if you want to see a dermatologist (again no appointment required).
Bring back medical secretaries to do all the paperwork during/following a consult. My private specialist always has his assistant in the consult and she takes notes and does the follow-up letters etc. Old-fashioned but reduces the admin burden for the doctor. Speeds up the consult too.
If there are not enough GPs, we need to do everything we can to reduce their admin load to free up time for them to see the patients that need them.