I am a compulsive puzzle and problem solver and the Books part of the Times on Saturday keeps me going for a long time. Today I got stuck on the last clue of the simple crossword. Eventually, being unable to solve "ornamental knots", I googled "list of knots" and found the Turk's Head, which is illustrated here.
A reader has recommended the following two sites for solving crossword puzzles.
The Crossword Solver lets you search for words where you know some of the letters and I use if also for the Codeword, where numbers represent letters. OneLook's Reverse dictionary lets you describe a concept and get back a list of words and phrases related to that concept. I have just found a site called Crossword Bebop that will keep me interested for a long while. It includes a good video on Twitter.