There must be only one possible solution to a Cryptarithm. Check, for instance, that any letters occurring once only are not in the same column. For over 400 years, cryptographers have been writing on the subject seriously. Systems once thought to be unbreakable have succumbed to analysis. Without a thorough knowledge of what has been done, and of what makes a good system, the chances of inventing a new one are slim.
Variations are endless and too often worthless.
Below is a list of guidelines for a successful military cipher. Variations for diplomatic and commercial use are minor, but in any case the ciphers are intended for heavy traffic use with difficulty of solution appropriate to the timeliness of the enciphered message. Few cryptographers are able to judge the weak spots of a system, even one that seems to meet the requirements. To be considered seriously, you would first have to describe your new cipher in an explanatory article. Based on this, and your own record of ability in cryptography, the system might be considered for acceptance for regular use if the reaction of the membership was favorable.