Games!
Gareth Metcalfe has some fantastic resources on his website to help develop children's multiplication and division skills.
These doubles cards are great for enforcing the 2x table.
These subitising cards are to help children develop fluency with their times tables (up until 9x table)
See the video here:
This is a game originally from NRich. It is great for developing children's fluency and understanding of multiples and factors.