Emma's Rectangle Merchandise Designs

I was recently contacted through my brand The Prawn Shop, by the talent agency of youtuber 'Emma's Rectangle' for a paid commission for 3 merchandise designs.
After looking in to who Emma is, and the type of videos she creates, i found that Emma is a plus sized life style blogger, i felt that this brief would be appropriate for the type of designs i like to create as my work centres around women and body diversity.

I responded to the email the next day, after deciding on a price for my designs; i assumed the merchandise would be t-shirts and hoodies as that is what i produce on The Prawn Shop & so i set my price at £200 per design, i came up with this price after using my knowledge of selling clothing;  i evaluated the average printing cost of a t-shirt (£6) the average sale price (£15) and calculating how many sales it would take Emma to make profit after the cost of the designs (66 t-shirts sold before profit). I assumed that it wouldn't take long for Emma to sell 66 t-shirts due to her 200,000 subscribers.
After not receiving a response after 3 days i emailed again, asking if my price was too high, they then responded and informed me that the designs would be for mugs and so they asked if i would be able to create three designs for £300, i negotiated and the price of £450 was agreed for the three mug designs.

After agreeing to the commission, i wrote up a contract and sent it over to Emma's talent agency (as seen below), after countless ppp sessions warning us about clients not paying designers, i wrote in the contract that i would need half of the total payment before designing anything, and then the second half upon completion, i also wrote in to the contract that if Emma chooses to pull out of the commission then i would be paid for the work that i've completed.
The contract was signed and sent back to me, and the first payment had gone through, it was then time to find out exactly what Emma would like designing.

We arranged to have a phone call, which then turned in to a facetime call which actually worked out better as i could see the personality of Emma and see small details about her such as the jewellery she wears, which would later inform the designs.
I wrote up a list of questions to ask Emma, however once the call began Emma was answering the questions before i even asked, telling me that she wanted bright rainbow colours and the type of design she wanted for each mug, what was quite useful was the fact that she was showing me examples of my own work (taken from The Prawn Shop instagram page) and the elements she really liked from different designs.
Emma had a clear vision of how she wanted each mug to look, which is great for me as their is no confusion about the design concept, colours to use or anything.
Below i have written up a a brief description of each of the designs.
(note to self: next time i talk to a client over facetime/phone call, record the audio as it's quite difficult to try and keep up taking notes)