Here are some tips on how to decide what to put in storage when moving:

Consider your needs. What items do you use regularly? What items can you go without for a while? What items are too big or bulky to fit in your new home?
Think about the future. Are there any items that you may need in the future, such as baby clothes or furniture? Are there any items that have sentimental value, such as family heirlooms or photos?
Evaluate your budget. Storage can be expensive, so it is important to only store items that you really need to keep.
Here are some specific items that you may want to consider putting in storage:

Seasonal Items. If you live in a climate with four seasons, you may want to store seasonal items such as winter clothes, holiday decorations, and sports equipment.
Large furniture. If you are downsizing to a smaller home, you may need to store some of your large furniture items, such as beds, sofas, and dining tables.
Hobbies and recreational equipment. If you have hobbies or recreational equipment that you don’t use on a regular basis, you may want to store them. For example, you may want to store your golf clubs, skis, or fishing gear.
Collectibles and Artwork. If you have collectibles or artwork that you don’t use on a regular basis, you may want to store them.
If you are unsure whether to store an item, it is always better to err on the side of caution and keep it. You can always get rid of the item later if you decide that you don’t need it.

Here are some additional tips:

Create a list of the items that you are considering storing. This will help you to stay organized and to make sure that you don’t forget anything.
Label all boxes clearly with the contents of the box and the room where the item belongs. This will make it easier to unpack your belongings when you are ready to move them out of storage.
Store your belongings in a climate-controlled storage unit. This will help to protect your belongings from damage.
Visit your storage unit regularly to check on your belongings. This is especially important if you are storing seasonal items or items that are sensitive to temperature changes.
By following these tips, you can make the decision of what to put in storage when moving easier and less stressful.