Hi degroote, have only a moment before my youngest totally loses patience, but I'll just give you my experience.
We potty trained DD1 during summer hols so she was (by her own choice) naked a lot during that time. I didn't use pull-up pants personally as I think they can be confusing. I reasoned that if she had an accident (which is inevitable) she should be aware of this (though not that she should feel ashamed, obviously)
We bought some books for DD1 and she was geared up for the idea. We made a fuss of the big girl pants, and she got to choose which ones she wore. She was already able to sit and produce a wee on her potty, having done this in the evenings before bathtime with success for about 6 months before we went onto full scale potty training (personal situation, moving house, moving country, starting new nursery meant we didn't follow up on this sooner).
We made a huge deal of the successes, barely mentioned the accidents and luckily all around us did too. Grandparents were very tolerant of receiving random phone calls saying 'I did a wee!' and neighbours were often greeted with stories of her progress. She felt very grown-up and proud 
On the advice of Gina Ford (not that we have done everything GF with the kids, but this made sense) we accepted that we would have to put some things on hold in the first two weeks and only did very short trips out, taking plenty of changes of clothes with us and being prepared for accidents in the car seat (which luckily never happened!). We gradually built up and up on this but whenever DD said she needed to, we basically stopped everything so that she could go asap. And that has meant some weeing by the roadside, though she is now able to hold it if she needs to.
Good luck!