Does how much you spend on clicks increase your CTR? Or is it just based on the percentage of click-throughs vs. impressions.
Than try improving your ad copy or rethink about your targeted keyword. Content match option is there in Google AdWords, the CTR becomes low when you have more number of impressions than clicks..... in content match maximum time the CTR is not so good.
I use thousands of keywords, don't know what people will search for so use keyword tools to create every word I can think of.
Than go and search for what are the results you can see out of it... it's like if I want my keyword as Hollywood hotel and I also take say keyword hollywood guesthouse than definitely I will get more impressions and less clicks.
Just to add one more point.... The ad copy must be good and if landing page is good it must be good in conversions also.
Use the {keyword} feature so you display there search term in your ad and run multiple ads, Google will use which ever one performs best.