In the CPE (CAE) speaking the examiners look at 5 criteria to give you your CPE / CAE mark. These criteria and what you need to do to get a high mark are ....
Grammatical Resource (5 = Do you use a wide range of grammatical structures?)
Lexical Resource (5 = Do you use a wide range of vocabulary?)
Discourse management (5 = Do you speak with very little pausing and do you use a range of cohesive/linking devices?)
Interactive communication (5 = Do you interact with ease?)
Pronunciation (5 = Do you use things like intonation, rhythm, stress to help make your ideas clearer?)
On the LC Langauges site you can find
Many topics with lots of less common words and idiomatic expressions to get a 5 in lexical resource. : click here
Questions like in the CPE (CAE) exam so you can practice using these expressions to improve fluency and lexical resource. (as above)
Grammar structures in the questions for a 5 CPE / CAE grammar mark (as above)
Example answers with 5 intonation and pronunciation so you can listen and repeat to improve your pronunciation: click here
Interactive videos so you can learn more about how to use less common words and idiomatic expressions. Such words and expressions have this sign ^, so when you see ^, learn to use the ^expression to improve your CPE / CAE lexical resource mark!: click here
Cohesive devices (linking / signaling words) so you can use a range to get a 5 in Discourse management. These expressions are underlined in the texts. So use the underlined expressions to improve your CPE / CAE Discourse management mark! (As above)
Example videos with learners like you using the words and grammar structures from this site.