Businesses such as bowling alleys, soft play centres and casinos can now reopen in England as lockdown rules ease.
More beauty treatments, small wedding receptions and live indoor performances can also resume.
The further lifting of restrictions comes as the government introduces bigger fines for failing to wear a mask in places where it is compulsory.
Meanwhile, thousands of holidaymakers have rushed to get back to the UK to beat French quarantine rules.
The easing of lockdown rules was postponed from 1 August due to concerns about a slight increase in the number of people testing positive for coronavirus in England.
Last week, figures from the Office for National Statistics showed this may be levelling off.
However, the latest government figures released on Friday showed the number of daily positive tests in the UK was the highest it has been since 14 June.
In the 24-hour period up to 09:00 BST on Friday, there were a further 1,441 confirmed cases, taking the total number to 316,367.
Under the latest changes:
- Indoor theatre, music and performance venues will be able to reopen with socially distanced audiences
- Wedding receptions in the form of a sit-down meal for up to 30 guests will be permitted
- The piloting of a small number of sporting events to test the safe return of spectators will resume, commencing with the final of the World Snooker Championship at Sheffield’s Crucible Theatre over the weekend
- Casinos, bowling alleys, skating rinks and soft play centres will be allowed to reopen
- “Close contact” beauty services such as facials, eyebrow threading, eyelash treatments, make up application and microblading will resume
- Pilots will take place at conference venues ahead of the expected resumption of business events from 1 October at the earliest
The prime minister said that plans to open up more of the economy this weekend “will allow more people to return to work and the public to get back to more of the things they have missed”.
But Boris Johnson reiterated a warning that the government “will not hesitate to put on the brakes if required, or to continue to implement local measures to help to control the spread of the virus”.
In England, face coverings are mandatory in many indoor settings, including public transport, shops and museums, with some exemptions for children or on medical grounds.
Under current guidance, people who refuse to wear a face covering where it is required face a £100 fine, which can be reduced to £50 if paid within 14 days.
The new enforcement measures will see that penalty repeatedly doubled for subsequent offences, up to a maximum of £3,200.
The latest easing of restrictions will not apply in areas where local lockdown measures are in place, the government said.
Local lockdown rules vary from place to place, but since July measures have been introduced in Leicester, Preston, East Lancashire, parts of West Yorkshire, Greater Manchester and Aberdeen.
The Department of Health said restrictions on household gatherings in parts of north west England, West Yorkshire, East Lancashire and Leicester will continue.
Devolved administrations in Scotland, Wales and Northern Ireland have the power to set their own timings for the easing of restrictions.
Are you getting married this weekend? Or are you preparing to reopen or go back to work? Share your stories by emailing [email protected].
Please include a contact number if you are willing to speak to a BBC journalist.