When designing a logo for a race, event, concert, or company where t-shirts will figure heavily in the mix, here are some considerations:

1. Don’t make it a full color or rasterized image. The logo should be a vector file so that it reproduces in bold color with clearly defined colors.
2. Minimize blends. Blends are easy to do with a computer art program of any kind. This does not mean they are a good idea. They are hard to print on t-shirts and usually an extraneous expense, not a thing of beauty.
3. Odd placements may be costly or even stupid looking, not creative. Designing a logo that goes over the shoulder from the front to the back of the shirt? Brilliant and unique, right? Wrong!!!!! I see this nearly every day and endlessly point out to people that this is not by itself “creative” (note I see this every day, thus negating the concept of it being creative…)  Nearly always this will not look at genius in real life as it does on a mock up on a computer screen. Quite often it involves some interplay of the front and the back which might be interesting except that people are not flat, they wear jackets and coats over their shirts, and you almost never get to see the front and the back of the shirt at the same time in real life like the mock up shows. Then you can add in the great expense and the requirement that every size of shirt will need a different size of art. There are times that a wrap around design, all over design, front to back concept or irregular placement are brilliant. However, for every one of those there are hundreds that are not.
4. Complicated is not good. If the logo requires numerous pantone matched colors and can only be reproduced with ten colors it is not a good logo. A good logo should not only be ok in full color but should have simple variations that are possible. Can the logo be printed in one color? Can the logo be digitized to be embroidered? If the answer is no then think long and hard about whether this is a good logo.
5. Don’t put tiny details in there. If you put parts of the logo that need can only be viewed with your glasses on and up close, this is a bad idea. Folks wearing t-shirts don’t want more than a very few select people to violate their personal space… If you can’t see what is going on with the logo from about six feet away then it probably is too detailed for a shirt design.
6. Including a background color as a necessary part of the logo will make for not great t-shirts. If you design with a square of color that sets off the color, usually that has to be printed and on a t-shirt that means a big non-breathable plastic film of ink. A design in a big square of color will rarely look integrated into the shirt, it will look stuck on there. A t-shirt is not a rectangle like a billboard, page in a magazine or web page. A version of a logo that will be used on a t-shirt will want to integrate into the shirt.
7. Don’t get overly clever with the font. Remember that besides looking good that the purpose of the shirt might be that people read that it is the Pawtucket Film Festival, not a clever design exercise.

I ran into a great article by a Mr. Gareth Hardy on logo design at https://www.smashingmagazine.com/2009/06/10-common-mistakes-in-logo-design/  His general advice is quite good and most of it applies to t-shirt design.