Want to seal a bag and don't have any plastic clips (or binder clips)? You can make your own bag clip using just two plastic straws.
The instructions from WikiHow are very simple and straightforward: cut one straw lengthwise, then fold the top of the bag you want to close over the other uncut straw. Slide the cut straw over the folded package. Really want to go nuts? You can make a fancy flower-y thing at the end of your makeshift bag clip.
Make a Bag Clip from Plastic Straws [WikiHow