We always make homemeade costumes, so my daughter picked hot air balloon.  I thought to myself, how am I going to pull this one off (previous costumes have been John Deere tractor, bowl of macaroni and cheese), so I knew with some thinking I could get it accomplished.  First I went looking for the perfect basket!  After hunting around town for a week, I found one at a thrift store for $3!  I bought 4 dowel pins to place in the basket as the ropes.  So we first cut out the bottom of the basket.  Then placed the dowels in the basket and zip tied them in-since the basket was rectangular, we did not put them in the corners or the balloon part would have had to be bigger than my vehicle to look proportionate.  So we put them in where it would be square and proportionate.  Then we made the wire form.  We attached the wire to the top of one dowel pin and made a tall rounded look and hooked it to the dowel diagonally from it.  Then we did it again with the other two.  This was not enough to get the shape we were going for, so we took the wire and made a circle a 1/4 of the way up the wire structure-we attached this wire circle to the other wire with zip ties.   Then from the circle wire, we made two more loops up to get the balloon shape we desired.  We had an old tubular kite that we used as the balloon part-which worked quite well!  We slipped that over our wire form, sinched in where it needed it on the top!  Last, I took brown paper bags, put newspaper in them, tied them onto the basket at each corner to act as sandbags!  We also ziptied two push button strobe lights from the Dollar Store inside the balloon part so it would light up at night.  She won a costume contest and had hundreds of comments!