What type of clothes are easier to put on (such as an open back, etc.)? Looking for ways my mom’s caregivers can change her easier and safer.

If she's unable to stand and/or primarily in a chair or wheelchair then open back shirts, pants and undershirts and sleepwear are available, that's what I was requested to buy for my mom when she was in the nursing home. Like these

https://www.silverts.com/all-adaptive/tops/open-back

https://www.silverts.com/all-adaptive/pants/open-back-pants

I was able to adapt a lot of mom's existing clothes once I had a few items to use as a guide.

Try looking at Buck and Buck. They have many items that Velcro from the back. Also, they sell beautiful night gowns that are just like hospital gowns.

I bought mom about 20 pairs of hanes sweatpants with wide waste band and open bottoms. I got them from Walmart, under $10. These are easy up/down, on/off, comfortable, washable. Mom wears them every day and as pajama bottoms too. In summer we roll up bottoms to capri length. Mom wears depends and the sweatpants are roomy enough for those. My mom wears lightweight sweatshirts. I get them one size up because she likes looser fit plus she has curved spine and they are easy to put on first with hand guidance, then over her head. Plus the long sleeves protect her fragile arm skin from bruising. I found some on Blair website. They are tunic length with no band at bottom. Mom is generally cold all the time so she wears these year round. In winter she wears a soft cotton undershirt. Mom likes that there are no buttons snaps zippers velcro at all. Not sure what limitations your mom has but these may work. I hope you find something that works for you.

Pull on pants with elastic waistbands. Knit tops that are easy to pull on (wider necks and sleeve openings). Knit jackets and sweaters that zip or button in front.

There are online stores with catalogs that offer useful clothes and items for people who have difficulties. Google and take a look.

Simple button down front dress, cotton for summer and a heavier, warmer fabric for colder months. I expect that your mum will be from a generation where trousers weren’t really seen on women too much, possibly as a work uniform or worn by movie stars such as Bette Davis. Plus a dress is one item that you can dress someone in from the front, this means that your mum will see who is dressing her, will be able to see when she is being spoken to and more importantly, the person dressing your mum will be able to convey any discomfort they might be causing by the expressions on your mums face. Also a dress like this doesn’t have a restricted waist but will have some tailoring, neither does it have fastenings down the back that can dig in and be uncomfortable to sit in for any length of time. Perhaps, if you are clever enough or know someone that is, you could alter a dress that your mum already has or better still, pop to a charity shop, you would be amazed at what can be found. Or if you can sew, buy something from there that is too large for your mum but could be altered or the fabric used to make another dress. Beware though, some charity shops see themselves as purely business and forget that they provide a valuable service to customers who aren’t looking for designer labels finds or vintage pieces but just everyday clothes at affordable prices. These charities charge silly prices so it pays to shop around. Think of it this way, you have been unemployed for a long time but have an interview for a decent job that you want to make a good impression at. You wouldn’t have the money to just whip into M&S and buy a new suit but equally, not have anything already that would be suitable. Charity shops (or some) can cater for this, also you will be recycling and doing your bit for the environment.
Your mum may stay indoors most of the time but try and dress her in pretty colours and natural fabrics (easier to wash), who knows what she may the thinking really. Good luck with dressing your mum, I’m sure you will find something good for all, that you have thought about the carers shows that you are a lovely person, whatever you do will be done out of kindness

There are companies that sell clothing for those with limited abilities. Look online. I was researching pants for my husband who has Parkinson's and found several. Also try going to a medical equipment/supply store they may have information on local stores.

The Silverts catalog is what you want.

Elastic pants, loose pullovers or zipper front tops; slip on shoes.

Convert her nightgowns to hospital style gowns:
Cut down the middle of nightgown back (from the neckline to the hem). Turn under each side seam 3/4”. Press with an iron.
Turn under the raw edge so the 3/4” seam is now 3/8” and there’s no raw edge of the fabric. (If necessary, go 1/2” and fold to 1/4”)
Stitch with a machine or needle and thread. Add snaps to close.

I did this for someone and she was happy to have her nightgowns but they were now easy on and off.