Sotherton, who took a shock bronze in Athens in 2004 and agonisingly finished fourth in the Beijing Games, was forced into retirement by a back injury which ended her own home Olympic dream.
She told Eurosport that if Britain is to be celebrating another heptathlon medal this summer, Sheffielder Ennis must keep everything familiar.
"The Olympics is the pinnacle of the sport. The pressure there is more intense. And with it being a home Games, that adds more intensity: the two factors together make it massively intense," she said.
"But you don't have any difference in the process. The environment is different, but you need to keep the same rhythm, and not change anything. Keep things as simple as possible, the same as every time you do the heptathlon.
"Things can change with nerves and adrenaline, but you don't want to introduce anything new."
Ennis, the 2009 world champion and 2011 silver medallist, missed the last edition of the Games with fractures to her foot.
However Sotherton does not believe her lack of Olympic experience will count against her in London.
"I don't see Jess as much now that I'm not part of Team GB, but she's in great form. She recently had PBs or matched her PB in three of the events, so she couldn't be doing any better," Sotherton continued.
"[Missing Beijing] won't affect her - that's in the past. If you're the favourite, at your home Games and in the best shape of your life, it will make no difference to what happens."
Ennis, 26, broke Denise Lewis's British record in May, recording 6,906 points in a meeting in Austria. That included personal bests in the 200 metres and javelin, as well as equalling her PB in the long jump.
Sotherton, 35, is targeting next year's London Marathon as she recovers from surgery on the injury which ended her career.
"I'm undergoing rehab following the operation on my back, but I'm looking forward to getting back to full exercise as part of a healthy lifestyle," she added.
"I'm going to do the London Marathon next year, so I've something to aim for.
"We're opening a new ASICS store in London which contains a running lab, which is unique. It measures your physical attributes, VO2 Max and things like that, and analyses your running style on the treadmill - it can even give you an estimated time for the marathon or half-marathon or whatever distance you're planning to run."
Kelly Sotherton was speaking at the launch of the new ASICS flagship store on Oxford Street. The ultimate sports performance store features a cutting edge running laboratory - the first of its kind available to consumers in the UK. www.asics.co.uk