Usually does, if not the approach, certainly the mindset. Anyone who tells you that they've increased the number of contracts they're now trading with absolutely no effect on their psychology is probably lying thru their teeth.
Unless you're a 100% systematic trader, trading a predefined position sizing strategy, which is the only way I can trade. There is no change in my mindset from when I was trading 1 lot vs 8 lots... and I still have a full set of teeth
Some general comments. I'd say most intraday traders use the 5 or 1 minute charts, with most also paying a lot of attention to the 30 or 60, and also the daily. Many intraday traders like to watch a momentum oscillator like stochastics, although opinions differ as to how useful they are (hint: not very). Some like to run moving averages, others use moving average oscillators or MACD. I like to draw support, resistance and pivot lines on a 5minute chart and watch TICK, TRIN and PREM. There are many different ways to trade, and how well they work often is determined by the market conditions. For example, a breakout system will make a lot of money in running markets but will be a steady loser in a range-bound market. No one can tell you that "this" is the best way to trade simply because they have no way of knowing how the market will act. A pretty basic but sound approach is to use the 60 minute chart to determine the direction of any trend and then use the 5 minute chart to try to enter on pullbacks in that trend. It is highly recommended to use backtesting software to get an idea for how your favored approach has worked in the past.