I recommend the following approach:
1) Start with "Case in point" book - you can download this book for free everywhere. It's not the best guide on how you should approach the cases, however, it will give you the basic understanding.
2) Start practicing cases with partners here or find them locally
3) Practice fast math
- Learn how to multiply double digit numbers (https://www.youtube.com/watch?v=6ndkkPZYJHo)
- Learn the division table up to 1/11 (i.e. 5/6 = 83.3)
- Learn how to work with zeros (Hint: 4000000 = 4*10ˆ6)
- Use math tools (Mimir math for iOS), Math tool on Viktor Cheng website to practice
3) Purchase and read Viktor Cheng Book (Amazon Kindle store) and listen to LOMS (his website). I recommend to reread the book and listen to LOMS every 15 cases. Every time, having more experience, you’ll be finding something new.n
4) Every 10-15 cases revisit the previous cases and think how you would structure them differently now having the new experience and having solved the new types of cases
5) Build business judgment. Read about different industries and functions. I strongly recommend practice drawing structures for each industry - profitability, value chain, etc . Then I will switch to getting functional knowledge and key concepts in Marketing (Brand and trade marketing tools, etc), Supply chain (Ops metrics like cycle time and throughput time, distribution and delivery specifics, etc), Finance (Basic Accounting and Valuation). Good sources might be:
- Books - one good book about airlines with numbers and industry analysis can give you all needed industry knowledge
- Company reports, equity reports, etc - usually have a good overview of company and industries.One of the best sources to prepare
- HBS cases - quite useful, but not sure if lot's of them available publically. Probably worth buying
! Important 1: practice the tests / written cases for the relevant companies. ( https://www.preplounge.com/en/consulting-forum/ranking-available-mckinsey-pst-resources-1432#a3116
! Important 2: don't forget about the FIT interview part. Crafting you stories and backups stories will require a couple of weeks!