From crashMATHS, note the A Level Practice Papers and mark schemes, this looks like a very valuable resource. There are several papers and mark schemes available with more coming. Versions are provided for AQA and Edexcel, these use the style of papers we see from the exam boards. Currently, there is nothing for OCR. For Mathematics the content is the same for all the boards and for Further Mathematics we have a prescribed core that must comprise approximately 50% of its content. This common content as we have with GCSE is very useful indeed as we can use resources from all the examination boards.
Also from crashMATHS, these AS Maths Key Skills checks and 2019 AS & A Level Question Countdown sheets are excellent. See AS Level Question Countdown and/or the A Level Countdown. Each set provides 10 worksheets of mixed questions with 7 questions on each sheet, 5 are pure questions and 2 are applied. Whilst written in the style of Edexcel, the subject content is the same for all examination boards.
I do like the way the pure section of the worksheets includes a mix of basic, problem and modelling questions.