Raising the tax threshold - all well and good, but could you feed a family and rent a house (not social housing, almost impossible to get in my town) on £12k - £16K pa? Even if you weren't paying any tax? The tax that is paid on a £16k income nowhere near makes up the full amount of benefits that someone on that wage receives to survive (what even the government decrees is necessary to survive at just above poverty level).
Whoever said about bus passes for the disabled - not everyone who gets a free bus pass on the basis of their disability is also entitled to DLA. I'm not. The reason I'm entitled to a bus pass is because by law I cannot hold a drivers license until/unless I am seizure free for a year. So it is to enable me to get around without bankrupting myself.
Charging disabled people/elderly 10p for a bus journey would be subjective - if it was down to the driver, most people with epilepsy or other 'hidden' disability wouldn't get the reduction in fare, only those with visible disabilities. If you had a card to prove your entitlement, well someone's got to administer that. If the bus comany was forced to only charge 10p, they wouldn't be able to take as many passengers, so would not cover their overheads, thus putting people out of work.
NOT everyone practices tax avoidance - I can't think of one example in my life where we tax avoid. We don't have an ISA, can't afford to pay into a pension, don't do work cash in hand, we don't donate to charities through gift aid (we do coffee and cake mornings and donate that way, in cash made). Why can Big businesses get away with not paying their taxes.
Overhaul the entire tax system, simplify it, make it impossible to avoid or evade taxes.