The reality and short answer is that any idea you would start with will most likely change, so it does not really matter.
Yet, there are unlimited ways to form an idea. For instance, you may check out the following links to see if you would see any pattern to assemble or bridge any two compartments or components together such that it would very simply solve a problem at least 10 times better than other solutions, products or services.
If I were you I would not go to a direction of others opinion, especially when in comes to startups although final projects are okay for temporary work.
If I were you I would also search in other external departments to see what problems they have, even small, that you feel you can contribute to or form a small team (3 is the best) to solve it because usually they have such problems that we have never considered that a problem, and it can be solved in less that 2 weeks, and with proper hardworks can turn into a successful startup or small business.
It is resource-based and it depends on the way you do it, not the ones others speak of. Because no matter what, there will come a day that it become fairly or highly difficult to push a startup forward that if you would not have initiate it, find it, or choose it, you would most likely give it up (94% usually give up, not to mention only 1% succeed well). Thus, everything else you may let go, but initial direction is best to be either yours or opinion of your co-founders/team, whom you truly believe in. It is similar to an analogy that one to become a football or a rugby player since they are fully different sports.
It is worthwhile to mention that many industries in the tech sector are currently challenging with innovation, however startup venture investors in the US highly dislike innovations and I have communicated with a large portion of VCs. So, if you are looking for too much "innovation", you may need to find "channels" to large corporates for very early stage or unlaunched business acquisitions.
All set aside, there are vast trending Artificial Intelligence, Data Analytics, Cybersecurity, Financial Analytics markets that can be reverse engineered to many innovative products or services, applicable to several sectors, including but not limited to tech, medical, IT, manufacturing, defense, security, finance, banking and insurance among others. However, my opinions are upon my experience being in the US and I am sure there are other ideas that would fit in the U.K., if thats where you may plan to grow a business in the future.
My advice to anyone who wants to do startups is "not to do it", even though I continue to do, fail, and redo :).