Shoppers queued early as non-essential retailers across Scotland prepared to reopen their doors.
Shops with on-street access and some workplaces such as factories are reopening following further easing of lockdown.
Small weddings and civil partnerships can be held outdoors and zoos can reopen, but only to local visitors.
However the first minister urged people to act responsibly and "not to squander" Scotland's progress.
The resumption of non-essential retail is one of the biggest changes to restrictions to date.
It is the first time many stores will have had customers since the Scottish government lockdown came into effect on 23 March.
A queue formed outside Glasgow's Primark store on Argyle Street at about 05:50 even though it was not due to open its doors until 08:00.
BBC Scotland News reporter Graham Stewart said there were about 100 people there.
He said: "The line stretched from the entrance on Argyle Street all the way round the corner into Miller Street and half way up that road.
"Many customers said they were shopping for essentials like underwear and socks - others were just happy to get out the house and back to some normality.
"No-one I have spoken to has health concerns although a small number are wearing masks."
Marks had been placed on the pavements to ensure customers were distanced two metres apart and the shop was letting in customers in batches of around 10 people, leaving the store by a different exit.
There were also queues outside Primark in Edinburgh's Princes Street and in Aberdeen's Union Street.
Queues outside Primark in Aberdeen, as some non essential shops begin to open their doors again. pic.twitter.com/IQhOQgokp0— Robbie Boyle (@robbie_boyle) June 29, 2020
Ahead of opening time, Nicola Sturgeon tweeted to remind people to observe the rules.
She said: "If you plan on visiting shops today, please do so responsibly. Maintain physical distancing, follow hygiene advice, wear a face covering and respect staff who may be asking you to shop differently.
"We've made so much progress against the virus - let's not squander it."
Monday's easing of the rules forms part of phase two of the Scottish government's "route map" out of lockdown.
Further restrictions are due to be lifted later this week.
Indoor shopping centres must remain closed for now, except where they contain essential shops.
But outdoor markets are also able to open.
'Not Boxing Day sales'
Scotland's national clinical director Prof Leitch said he was looking forward to people going to the shops and supporting local businesses but he warned: "It is not back to normal.
"This is not the Boxing Day sales."
Healthcare premises such as optometry practices are also now able to see patients face-to-face for emergency and essential eye care.
Many practices have continued to provide remote support for patients during lockdown and throughout phase one, but will now be able to start seeing patients again in person.
'Thrilled to open'
Factories, warehouses, laboratories and research facilities are among workplaces that can reopen, provided guidance on social distancing measures are in place.
But non-essential offices and call centres have to wait until phase three before they can reopen to staff.
It is now also possible to go to outdoor sports courts and children's playgrounds.
Outdoor visitor attractions such as zoos and safari parks, along with gardens can reopen, but for local access only - "broadly within five miles" - until a further easing of restrictions expected in early July.
The Royal Zoological Society of Scotland (RZSS), which owns Edinburgh Zoo and the Highland Wildlife Park, along with the owners of Blair Drummond Safari Park near Stirling, had been calling for a reopening date before the end of June.
The safari park said the months-long closure had "pushed it towards a financial cliff".
RZSS had warned that missing the start of the summer season could see it lose a total of £500,000 in funding for its sites within five weeks - £400,000 at Edinburgh Zoo and £100,000 for the Highland Wildlife Park near Aviemore in the Cairngorms.
David Field, RZSS chief executive, said the society was "thrilled" to be able to reopen its attractions.
He said: "Safety comes first and it is important everyone follows the government guidance to protect themselves and others.
"At the moment, current guidance asks everyone to stay within their local area and defines this as broadly within five miles.
"We are pleased to hear that from 3 July the travel guidelines may be relaxed to allow people from further afield to visit too."
Marriages and civil partnerships are now allowed outdoors, with limited numbers.
Registration offices can open for high priority tasks.
And restrictions on moving house have also been relaxed.