Jason Roy says that the major aim of England's one-day tour of South Africa will be to maintain the confidence that has been surging through their white-ball cricket in recent months, as they build towards the World Twenty20 in India in March.

Roy, who scored his maiden ODI hundred at Dubai in the final match of England's 3-1 series win against Pakistan in November, has cemented his role at the top of the order in both 50- and 20-over cricket, forging an aggressive and productive opening partnership with Alex Hales.

However, Roy concedes that the conditions that England will face in South Africa, where they play five ODIs and two T20s, starting at Bloemfontein on Wednesday, will be quite unlike anything that will be on offer in Mumbai and Delhi, the venues for England's group stage fixtures in the World T20.

The onus, he says, will be on maintaining the winning habit that England have instilled in their limited-overs cricket, ever since their ignominious exit from the World Cup in Australia and New Zealand this time last year.

"We've got an honest squad, a healthy squad and a squad that works harder than I've ever seen people work," Roy told ESPNcricinfo during an event for Slazenger Cricket. "We enjoy each other's company which helps, we know each other's games and we are brutally honest, so I think that's a huge positive for the England dressing room at the moment."

England have won two out of the three completed ODI series since the World Cup, against New Zealand and Pakistan, and five out of five T20s, with the most recent, against Pakistan in Sharjah, being settled on a Super Over after the scores finished level in normal time.

"What this series will help us do is build our confidence before we go out there," he added. "Because that is what will help us compete. In Twenty20, for me, it's 90% about confidence. As an opening batsman, if you are going out there low on confidence you are nowhere. You are no use to anyone."

With that in mind, Roy starts the tour in an ideal frame of mind, following his match-defining 102 in Dubai before Christmas.

It was, by his usual standards, a relatively hard-working innings - he took 64 balls to reach his first fifty, and 117 balls all told, setting the stage for Jos Buttler to round the tour off in explosive fashion with an England-record 46-ball hundred. But Roy says, the experience of reaching three figures in an international match means so more than mere figures can convey.

"A lot of my batting is about instinct but, once you get yourself in, it's about constructing an innings," he said. "You have to be that much more precise at international level, so it was an amazing feeling to let myself know that I could do it and, now that I've done it, I hope there's plenty more to come. It's not the absolute be-all and end-all, but I'd like to believe there's a big hundred in me in the near future.

"I was conscious that it was going to take more energy to get to three figures in the UAE, because your approach to places like that has to be completely different to Australia, England and South Africa," he added. "In England you can hit on the up, in the UAE you have to take a more measured approach.

"If I woke up in the morning and someone said, 'here's a hundred at a strike rate of 85-90', I'd be like 'yeah, man'. I'd rip their arm off every day. I'm not fussed if people say that's not the way you normally play because if that's the way I've got to play to get a hundred, I'll do that every time."

Roy's arrival in the England set-up has coincided with an upsurge in the team's fortunes, but right from the outset he has been a beneficiary of the more relaxed atmosphere that has been instilled by the new regime. His first ODI innings was a case in point - a first-ball duck against New Zealand at Edgbaston, in the very same innings in which England racked up their highest ODI score of 408.

"I don't really remember it for the first-baller, I remember it because we won my first game," he says. "But my first series was an extremely eye-opening experience. My top score was about 40 [39], I wasn't a success really, but they told me at the start of the series, 'mate, this is your spot, good luck' and I just tried my best. Unfortunately it didn't come off then but I got another chance against Australia and got the boys off to a few good starts."

With Eoin Morgan coming into his own as a captain, alongside the coaching partnership of Trevor Bayliss and Paul Farbrace, England's one-day cricketers are being given more licence to play their own games and hang the consequences. That plays nicely into the hands of a natural strokemaker such as Roy.

"I've got such a lot of respect for Morgs," said Roy. "If you've got a huge amount of respect for someone and get on with them you'll go the extra mile. It's similar in the Test stuff now with Cookie [Alastair Cook], everyone's just gelling together, really working for each other. The individual performances are helping but it seems that in white-ball and red-ball cricket everyone is really working hard as a team."

That hard work is sure to be redoubled in the coming weeks, as England build towards the World Twenty20 with the sort of purpose and direction that was manifestly absent from their preparations for the World Cup this time last year. Roy, however, who has never yet played international cricket in India, let alone at a major tournament, admits that he is about to enter into the unknown.

"I don't know how we prepare for [the World T20] to be honest," he said. "We'll go out to South Africa and speak to the coaches and the players who've toured there a bit, and see what they know. It's not the sort of place where you can just have a few nets sessions and go out and have a slog.

"It's somewhere you've got to get your head round, not just the cricket. It's the environment that is extremely tough - huge crowds, loud, hot, really intense. I'm looking forward to learning more about my game."