You need to create an account to submit your designs at 110Designs graphic and logo design marketplace. After you signed up, just find a contest that you want to participate and click on Submit Design button. Here you can upload your design by clicking the Choose File button in and select your designs in .JPEG/.JPG, .GIF or .PNG format and then click on Submit Design button.
Make sure you follow the below guidelines before submitting your designs:
Failing to abide by the guidelines might result in your prize-money deduction, permanent account banning, legal action against you and more that depends on the type of violation occurs.