I remember when I finally came to the realization that controlling light was the key to getting good video. I did not have enough money to get a good 5-in-1 Reflector/Diffuser kit at the time, so I put together my own little collection of cheap alternatives. These included white sheets, silver dashboard reflectors made for cars, cardboard covered with tin foil and anything else I came across that could do the job. It got me through for quite a while, although I probably did not wow any of my clients with my professionalism.
My current 5-in-1 kit cost me about $100 and I use it on nearly every shoot in some manner or another, either as a bounce, in front of a light, as a flag, as a wind block for microphones, or any number of other ways. If you do not have one because of the cost, check out this option for only $12 through an Ebay seller. I have not used this set before, and I am pretty sure that it is an inferior product. But at this price, it could be disposable and still be a good buy. Here is an image to show what a reflector can do to add fill light to your subject when shooting in sunlight.