OP, if you haven't already done so you could maybe read books such as -
E H Carr, What is History?
Marc Bloch, The Historian's Craft
Fernand Braudel, On History
Peter Geyl, Debates with Historians
Some of these have modern editions with introductions by later historians, for example Richard Evans wrote an introduction for the latest edition of Carr. There are I think a couple of collections of essays by young historians commenting on Carr.
G R Elton wrote a response to Carr but I recall it being a bit grumpy, and very Elton-ish.
Try to familiarise yourself with the work of one or two of the great Oxford historians. For example, AJP Taylor, Hugh Trevor-Roper, Christopher Hill, Keith Thomas, and Niall Ferguson.
If time permits, maybe look also at works by E P Thompson, and Fernand Braudel.