Put the keys in one of the containers and throw the whole box on the floor. There must NOT be any places in your room/space where the containers may disappear without any possibility to retrieve them while bound.

To make releasing yourself more difficult, you may want to:

• Put wrong keys or something that sounds or weighs like a key in other containers.
• Pour water in the containers and freeze them (that will also add some initial time).

Now tie yourself up using the lock(s) the key(s) from which is in one of the containers. Think carefully and do not overestimate your abilities to move around. Now to you have to crawl from one container to another to find the right one or ones if you used many locks/keys.

If you are going to use blindfolds or closed hood, the area should be quite small, like a toilet or bathroom. A bathtub can also be used provided the drain opening is tightly corked up.

You can even use a not too tight sleeping bag. Get in, drop the containers inside the bag and zip it up. Now lock you hands behind you and try to find the keys ;-)

Do not forget that the keyholes must be reachable and face your fingers.