These are things I do with my clients.

There is not always a one size fits all way of organizing but these ideas generally work for most people.
Use labels on drawers, baskets or shelves. This works especially well for children when you want to teach them how to put things away. With labels there is no second guessing where things go!
Use clear storage bins with seal tight lids for seasonal items. Label the bins as specifically as you need to avoid having to guess what the contents are.
Color code your closet. Hang like colors together. This will save time and effort when selecting an outfit.
Use hanging storage racks with compartments for shoes and boots if you have limited floor space.
Don’t over stuff your closet. Select seasonal items and only the items you wear regularly and really like. Store the rest away in a storage bin or donate items you don’t need or care for.
Use a shoe rack. This allows you to see the shoes you have lined up in pairs. If you are a visual person, this will work well.
Use high shelves for hand bags, overnight travel bags or small bins of accessories youre not using often.
Fold T-shirts in half and then in half again then stack them according to color. This will save space in drawers or on shelves and reduces the time and effort in locating just the right shirt!
Purchase a jewelry tree for hanging necklaces. I have one and I love it because I can see what I have. I also use small “jewelry dishes” on my dresser for bracelets and other necklaces I wear frequently.
Lastly, always take inventory of what you have BEFORE you purchase something new. This helps avoid buyers remorse and it helps you to assess whether or not you have enough room in your closet for something new.