Most of the laughable tiling work I actually see is DIY or "mate did it" work. Most of the bad work I see done by paid tilers is poor or non-existant prep - waterproofing is a regularly avoided task and the most likely to need expensive rectifying within a couple of years - but I have had a lot of work out of that - 4 shower rooms re-tiled with proper waterproofing just in January. Even now I have 2 bathroom re-tiles booked in where the re-tiling is only needed because there is a shower above the bath and leaks below. The second biggest problem is floor tile failures on wooden floors. That's a good 1 day earner to fill in the gaps left during the week so I won't complain too much. When money is tight customers look to cut corners with costs - but that rarely saves money in the long run. Yet I have 2 current customers delaying their work for a couple of months until they have the money to pay for the job to be done properly. There is also a lot of truth about customers wanting one tradesman to do the lot. I often get asked to do additional work because of my company's name - that's no problem I simply sub out to other tradesmen whilst keeping the overall management fees and tiling work for myself! Having said that there is a lot of cross over between trades - as a tiler you may have to screed, plaster, remove and re-fix plumbed fittings, remove and re-fit electrical fittings, employ carpentry skills to cut down doors and plinths for flooring jobs. How much or how little of that you are prepared to do does not make you a plumber, carpenter or electrician, but they are a part of completing the tiling work.