I'm selling t-shirts. Can I make a drawing of a photographer's photo without paying a fee to the photographer and place my drawing on the shirt?
This is not intended to be legal advice, and, cannot be legal advice, because I don't know you, your real business situation, and I haven't seen your work. So, I can't apply the facts of your situation to the law.
The most straightforward way to use someone else's work is to get their permission. Asking permission can be a great thing. You can introduce your self to someone new. You can explain how their work has influenced and motivated you. You can show how your respect other people's creativity. When you have someone's permission, than you will have the best legal predictability.
Getting permission is not always possible: you may not be able to find the creator, the creator may be unresponsive, or you may not be able to figure out who current has the right to give you permission.
When you use someone else's work to create your own new work, this new work can sometimes be a "derivative work". A derivative work requires the permission from the preexisting work's owner. To determine if a work is "derivative", the law will consider the amount of originality in the preexisting work, the amount of originality in the derivative work, whether any aspect may be in the public domain, and other factors. The law defines artistic reproductions as an example of derivative work. See 17 USC 101. Many times, even lawyers may disagree about whether a work is original or derivative.
From your two sentence question, it is impossible to know whether you are exercising the kind of independent artistic and creative judgment needed to create an independent work. You may wish to work with an experienced copyright lawyer. It may be possible, if you have examples of your work, to get some type of preliminary advice during an initial consultation.
The other option may be to restrict your work to those cases where you can either 1) get permission; 2) use photos where you can pay to obtain rights, and hopefully, indemnification for infringement; 3) use photos that you take yourself; or 4) use photos known to be in the public domain.
Finally, you should obtain a good business insurance policy. These policies vary. You should consider many policies to find one that will protect you from unintentional infringement, just ask insurance agents for a sample of the type of policy they would use for your type of business. One good clause to look for is "Advertising Injury" clauses, which help protect from unintentional infringement when advertising your own products. Again, working with an experienced lawyer to help find the best policy for your situation can be helpful.
As always, check information that you find on the Internet against primary sources, like your own attorney.