Intra-day volatility in the stock indices is very high. Lots of action. Although increased volatility can be more difficult, what I do is to focus on outside in trades - fade the fast moves. This gives lots of trades every session.
The downside of this approach is that when the market goes into trend day mode - and it can switch part way during a session - I need to only fade the moves opposite to the trend, trading only those that pullback enough. Trading shallow pullbacks means it takes longer to discover I am wrong - bigger risk and the balance between risk and reward may not meet my standards.