There are various secondary sources that you can use both online and in hard copy that cover the Parish Registers County by County, the easiest but the least reliable is the International Genealogical Index started 60 years ago by the LDS Church.
Parish Registers, the records of the parish committee, vestry comittees, churhcwardens etc are also deposited if extant in your CRO.
manoral records are an endless source and will also likely be at your CRO, use Phillimores atlas and index of parish registers and the Vistoria County Histories, also in yourt local library, to identify the manor or parish relevent to your family.
i could go on but i am watching tele, let me know when you have exhausted this list.