Free is a friendly sort of word. It makes you smile. When it is used in the phrase Free Email Templates it should make your smile even broader. Not only are they free, that word again, but they are quick and easy to complete. More of a broad grin in all probability.
With the mechanics of the design completed for you all you need to worry about is the creative side. You could, of course, pay for an outside agent to do the necessary but that will probably seem a little extravagant in these times, even with the low overheads in bulk email marketing.
You might not know much about graphic design. I studied it for four years and came out the end knowing little more. As I had scant natural talent I looked for and found an easy design method: copy and change a bit.
It is no good just cutting and pasting. You would fall foul of a number of laws but there is more against copying than fear of court. If you do something identical to your class leading competitor then you are going to be behind them at all times. To get ahead in this game you need to give the subscribers to your email lists something a bit special.
Work out what irritated you. Were you confused? Did you have to reread something? Were there enough pictures or perhaps too much text? The question is whether the subscribers to your email marketing lists will think the same. Experiment a little. In bulk email marketing a 1% improvement is massive.
Unfortunately you have not got a total free hand in the design. The overall impression your emails give should make it obvious to anyone familiar with your company that it was the source. Those on your email lists will probably have visited your website and previous customers will have seen your invoices and letter headings. Have a degree of similarity in appearance over and above the logo and banner.
Ensure that your website, your adverts, your email newsletters and your invoices are all recognisably yours. Reassure your readers.