It is very important to know that you are in charge and what comes with the whole 'you are in charge' thing. A thing to be careful here is that being in charge does make you the one who lead but not the boss of anyone so under no circumstance you have the right to act like a boss. Acting like a boss is one of the things that can ruin your conference and make people leave and that is probably the less possible consequences that such an action will have.
You have to realise that being nice to people can open many doors and can make things happen. The thing here is to be actually nice and honest and not slimy. If you come to a point that you will become slimy people will eventually abominate you and it will probably have the same consequences as being bossy.
What I learned so far as a member of FOSS communities being and acting as politician is never the right thing to do since people are not stupid and it is impossible to fool a lot of people for a long time.
Now if you come to a point that acting like a polititian or acting honestly but being hard to someone are the only two choices you have my advise is to act hard. So far I believe I won more acting honestly but hard and most of all I gain respect from people for that. There are cases that I lost but if you put well your case then anyone with common sence will understand your possition, for all the others personally I just didn't care and this is not by choise but by nature.
Returning back to the 'you are in charge' thing I must say that it is very important to have some structure planned with your team of how you want things to be done and seperate fields of responsibilities for each part of the team and keep inside your part of responsibilities.
Having a structure will save you from doing unnecessary things and will give you a route of what you want to be done. In certain points this will even show you how to do things. If you have some 'talended' volunteers noticing Trello or whatever tool you will use for organizing your conference, it will show them too how to do things and this will make your life even better and it will save you a lot of time.
Seperate responsibilities with your team mates or giving responsibilities to other people outside your closed team that you trust and believe that will have the job done(Yes Stathis and Thanassis I am talking about you) is also a great thing to do. Most people in FOSS(and not only) love to be trusted and to be given responsibilities, although I wouldn't count that as a rule so make a conversation with them and be ABSOLUTELY SURE before hand them over such a great burden. If it turns out that you gave someone to do something that he/she was not sure or did not want it will be a great backfire to what you organise and can easily be the dynamite that will explode the whole organisation you do if you won't be careful.
Finishing for today I must say that a real important thing here is to always have an eye to those people, as said in 'The italian job' be carefull because "I trust everyone. It's the devil inside them I don't trust" and by that I mean that there are several cases were people drop something without telling you or any other just because for some reason they cannot tell you or any other. My opinion is that is human nature and I have done it at least once and heard about it like a million happenning. It is not really a trust issue but more of a safety issue in order to prevent bad things from happening. Last but not least, if you trust some pople enough to give them responsibilities, give them freedom to do it their way.