For many homeowners, there comes a time when you want to downsize. Perhaps it's time to put the home on the market and move to a smaller house, or maybe you'll want to stay put but get rid of some of the clutter which has accumulated over the years.

A storage unit can be helpful for your decluttering or downsizing efforts. These units allow you to clean up your home or comfortably live in a smaller residence by storing unneeded items off-site.

First, decide what sort of storage unit you'll need. The unit should be large enough to store all of your belongings with enough room to comfortably maneuver your way through the space. Liz Alterman, writing for Realtor.com, says climate-controlled units are preferable if you'll be storing antiques or other items that might be damaged by extreme temperatures.

If you'll be moving furniture or other bulky items, it's best to find a unit which is easily accessible. You may also want to check with the storage company to see what measures they take for security and pest control.

Be prepared for the extra monthly costs of renting a storage unit. The real estate site Rent.com says the storage unit you get shouldn't strain your budget.

But that dent in your finances can easily be an incentive to go through the items in the storage unit. Sarah Little, writing for the self-storage company StorageMart, says it doesn't make sense to simply pack things away and pay rent to store them. Doing so might make your home more manageable, but it doesn't cut down on excess belongings. You'll get the same result by cluttering up the attic, basement, or garage with unneeded items, and you can do that for free.

Plan ahead before moving items to a storage unit. Sparky's Storage Solutions, a company in Amarillo, Texas, says this will make the process much less stressful by giving you more time to choose what you will store. It will also give you a sense of how much stuff you need to put away, which in turn will help you decide how large a storage unit you need to rent.

One common decluttering method is to separate unwanted items by how you can dispose of them. Some can be sold or donated, while others—such as worn-out or broken items, or unwanted personal items—should be recycled or thrown away. This process will help cut down on the number of items in your home before you decide what you want to keep and what you want to store.

In deciding what should be put into storage, make a list of essential items that you cannot live without from day to day. These could be kitchen tools or other functional items that you frequently use, but they might also be aesthetic items such as wall art that you enjoy seeing on a daily basis.

After choosing the items you plan to store, set aside some time for periodic decluttering visits to the storage unit. Lauren Thomann, writing for the self-storage management company Life Storage, says this process might take several days to complete, and that you might need an extra helper to remove some items.

Taking an inventory of the items in storage is a good way to understand how many things you have, and it will be an easy log to update. When going through your items, you can again decide what you can keep in storage, sell, donate, or throw away. You may also wish to move some items back into your home if you have freed up space to keep them.

Consider hiring a professional organizer to help go through your items in storage. This person may be able to help you with your decisions, especially since it can be an emotional process to get rid of some belongings.

Once you have gone through the items in storage, see how much room is not available in the unit. KW Professional Organizers, a Canadian business, says you can save a great deal of money by downsizing to a smaller storage unit after clearing out some unneeded items.

It's also important to consider how long you want to rent the unit. You may only need to rent a storage unit for a few months to help declutter your home or make the downsizing process easier.

Long term storage rental may be a good option if you have family heirlooms or other items you'd like to keep from taking up space in the home, but don't want to get rid of. Of course, these monthly fees can easily add up. Even if you decide to sell the items you are storing, it's unlikely that you'll recoup the money you spent on storage.