Opposite preschool lesson plans
Opposites:
up/down left/right hot/cold winter/summer white/black on/off over/under loud/soft soft/hard easy/difficult happy/sad wet/dry sink/float fast/slow open/closed more/less brave/scared here/there near/far stop/go in/out girl/boy high/low north/south east/west old/young old/new good/bad

Black and White Art
Use a variety of materials. The children can use black and white paint, make a collage, use crayons, markers, you get the idea. 
note: When something appears to be black it absorbs all the colors of light, where white reflects all colors of light.

Hot and Cold
Talk about the clothes you wear outside in the winter when it is cold and the summer when it is warm. Have the children create a summer scene on half of the paper and a winter scene on the other half.

The Opposites Hat
Cut out many square pieces of construction paper. On each one write and action such as: clap your hands above your head, 
stomp your feet loudly,
shout your name
reach up
stand up
jump up and down fast
etc
Put these papers into a hat or box and during circle time have a child draw a paper, and read what it says. The child will then do that action then have them to the opposite.

Opposite pairs
For older children you could show them how opposites are pairs... ie in, out up, down.

Inkblot Art:
Fold a piece of paper in half. Have the children paint on half, then fold in half again so that you have two opposite images.

Left/Right:
Do the Hokey Pokey. Concentrate on left and right.

Left/Right Art
Fold a piece of paper in half. Have the child create two different pictures on each half of the paper. You can also do this with the top and bottom halves of the paper.

Happy/Sad Collage
Provide the children with magazine with people and children in them. Have the children cut out the pictures and glue them to a piece of paper. Have the children tell you how each person feels.

Feelings Art
Ask the children to create a project that shows "happy" and "sad".

Happy/Sad Faces
Provide the children with a variety of precut facial features from magazines. Have the children glue the features on paper plates to create happy and sad faces.

If You're Happy and You Know it
If You're Happy and You Know it, Clap your Hands 
If You're Happy and You Know it, Clap your Hands 
If You're Happy and You Know it, then your face will surely show it 
If You're Happy and You Know it, Clap your Hands 

If You're Sad and You Know it, Say Boo Hoo
If You're Sad and You Know it, Say Boo Hoo
If You're Sad and You Know it, then your face will surely show it
If You're Sad and You Know it, Say Boo Hoo

Dump and Fill
Toddlers like to dump and fill just about anything. Be sure to supply the children with plenty of opportunities to dump and fill. Coffee cans and boxes make great items to be filled. You can have the children fill with toys, tops from baby food jars, and other toddler safe items.

Will it Absorb water?:
Supply the children with pieces of material to test like pieces of cotton, plastic, wool, tin foil, etc. Supply the children with eye droppers and a cup of water. Which materials absorb water and which do not? You may also decide to do this experiment as described in sink or float (below)!

Will it Float or Sink?:
Place a bunch of items on the floor. These items should be those that will be okay if they get wet, like blocks (plastic or wood) rubber toys, a pencil, a rock etc. Make a graph with four columns. List all the items in the first column, label the next column sink, the next float and the last results. Hold up each item and ask the children to decide if they believe the item will sink or float in water. Record the number of children who voted sink under the sink column and the number who voted for float in the float column. If you have a smaller class you could record the names of the children instead to see who is a really good estimator. Then test the item in a tub of water and record the result in the results column. Then continue with the next item.

Wet/Dry chalk art:
Soak some chalk in a bowl of water. Let the children use the chalk to draw with. Then allow the children to use dry chalk.

Maps:
Bring in some maps and talk about North, South, East and West. Where is your state/country compared to nearby states/countries?

Magnets:
All magnets have a north and south pole. These poles are opposites and attract each other. Have the children experiment with magnets and see of they can find two poles that are alike and two that are opposite.

Balance Fun:
Provide the children with a balance. Have them place objects on both sides. Ask which weighs more? Which weighs less?

Here/There:
Play the shell game with two cups and a toy. Ask the children is the toy here point to a cup, or there? You could also use left and right.

More/Less
Disperse similar objects to all the children. Give three to some, four to others, one to some, and so on. Take a couple for yourself. Then show the children how many you have. Ask who has less? Who has more?

Red Light/ Green Light
check out the rules here: Games Kids Play

Hide and Seek

Play hide and seek, check out the rules here: Games Kids Play

Mother May I?

Again, check out the rules here: Games Kids Play

Opposite Cards:

Create or buy index cards with pictures of opposites on them. You can play memory, have the children match them up, or pick partners with these cards.