I am well versed in Adobe Photoshop using it for both work as a Digital Designer for M and M Direct Ltd and for my own Martial Arts Club. In particular, I have created several clothing designs of my own for use on t-shirts, hoodies and even custom trousers. I have also completed fun designs for clothing for family members incorporating photographs, text, and applying different styles to these designs. Many of the designs I have completed include front, back and sleeve graphics. I can supply these at whatever size and file type required. Most of the designs I have done for clothing have been used as JPEGs and either screen printed, painted, vinyl printed or even embroidered.
Your specification states you would like your own current design adapted or built upon in order for it to be used for t-shirt printing. I am happy to do this and can present several designs from which you can choose from if you wish. I would love to have an idea of the purpose of the t-shirt to help understand the design better.
Please feel free to contact me if you have any further questions.
Regards
Adam