Template for Kekkai Genkai application is the same as in for Jutsu's, but there are few notes you must read before you can create your own bloodline.
You must not make anything even similar to Rinnengan and Sharingan. Anything similar to them will be denied immediately. Rinengan and Sharingan are admin gifted to good users or if you manage to obtain them through rping by stealing it from someone.
When you make a bloodline you are not making it just for yourself. If it is majorly spread it will become one of clans in your current village, if not you will still not be the 'only surviving' member of your clan. If we read that your bloodline is deleted without questions asked.
Your bloodline can have many states of evolution (Sharingan one tomoe, two tomoe, three tomoe, Mangekyo for example), but they all must have some similarity between themselves. If you say that one state gives you control over sand for example and in next state you summon demons from hell we will probably say WTH and deny your template. Keep it real and original to Narutoverse.