Any Advise Or Suggestion Please? Thanks.

Hello everybody,

I am a new member,
I’m AutoCAD designer and internet marketer.
If this is the right place to post my question then it is fine,
if not then I am sorry, and you can ignore it.

Some of my clients are painters and photographers.
They don't know how to market their artworks or don't have time.
So I’m taking care of promoting their artworks worldwide.

I see that the Premium Membership here can be a solution to manage everything in 1 place.
But unfortunately, the only 2 options I have to do this are:

1- For every client (artist), I have to load his artworks myself,
which means TIME CONSUMING for me.
OR
2- I have to give everyone of them my username and password.
In this case, there will be NO time consuming for me, but it can be RISKY

My idea is to allow each one of my clients to upload his own artworks by himself,
With this way I (as marketer) can focus on marketing aspects only.

Now my question is:
What is the best way (if any) to manage several portfolios of different artists using only 1 ArtistWebsite account?

Any advise, suggestion or idea will be very helpful.
If you ever have been in similar situation, thanks if you can share with me your experience.

Have nice weekend.
anouja.