If you are happy with fontification (as explained in http://lists.gnu.org/archive/html/emacs-orgmode/2009-05/msg00236.html) you can add the following to your .emacs. It adds fontification for some macros, such as some from biblatex, csquotes, cleveref and enumitem. If you want to add or remove macros from the configuration it is easily done, just check the manual.
;; Fontification
;; http://lists.gnu.org/archive/html/emacs-orgmode/2009-05/msg00236.html
;; http://www.gnu.org/software/auctex/manual/auctex/Fontification-of-macros.html
(setq font-latex-match-reference-keywords
'(
;; biblatex
("printbibliography" "[{")
("addbibresource" "[{")
;; Standard commands
;; ("cite" "[{")
("Cite" "[{")
("parencite" "[{")
("Parencite" "[{")
("footcite" "[{")
("footcitetext" "[{")
;; Style-specific commands
("textcite" "[{")
("Textcite" "[{")
("smartcite" "[{")
("Smartcite" "[{")
("cite*" "[{")
("parencite*" "[{")
("supercite" "[{")
;; Qualified citation lists
("cites" "[{")
("Cites" "[{")
("parencites" "[{")
("Parencites" "[{")
("footcites" "[{")
("footcitetexts" "[{")
("smartcites" "[{")
("Smartcites" "[{")
("textcites" "[{")
("Textcites" "[{")
("supercites" "[{")
;; Style-independent commands
("autocite" "[{")
("Autocite" "[{")
("autocite*" "[{")
("Autocite*" "[{")
("autocites" "[{")
("Autocites" "[{")
;; My custom cite commands
("posscite" "[{")
("Posscite" "[{")
("posscites" "[{")
("Posscites" "[{")
;; Text commands
("citeauthor" "[{")
("Citeauthor" "[{")
("citetitle" "[{")
("citetitle*" "[{")
("citeyear" "[{")
("citedate" "[{")
("citeurl" "[{")
;; Special commands
("fullcite" "[{")
;; cleveref
("cref" "{")
("Cref" "{")
("cpageref" "{")
("Cpageref" "{")
("cpagerefrange" "{")
("Cpagerefrange" "{")
("crefrange" "{")
("Crefrange" "{")
("labelcref" "{")))
(setq font-latex-match-textual-keywords
'(
;; biblatex brackets
("parentext" "{")
("brackettext" "{")
("hybridblockquote" "[{")
;; Auxiliary Commands
("textelp" "{")
("textelp*" "{")
("textins" "{")
("textins*" "{")
;; subcaption
("subcaption" "[{")))
(setq font-latex-match-variable-keywords
'(
;; amsmath
("numberwithin" "{")
;; enumitem
("setlist" "[{")
("setlist*" "[{")
("newlist" "{")
("renewlist" "{")
("setlistdepth" "{")
("restartlist" "{")
("crefname" "{")))
C-c RETandC-c C-e? If you only want fontification (e.g. syntax highlighting) for new commands see the heading;; Fontificationin the .emacs example in tex.stackexchange.com/a/50919/5701 – N.N. Dec 8 '12 at 9:40