What is the best visa strategy for a British citizen wanting to stay in Thailand for 90 days?

Hi. I am new to this group and looking for Visa advice. I am a British passport holder. I have been travelling to Thailand for many years and spending 30 days there every winter. The last couple of years I have obtained a 60 day Visa before leaving the UK and stayed for that length of time. This year I wish to stay for 90 days and have booked my flights. This is where I need advice. My intention was to apply for a 60 day visa before travelling, then apply for a 30 day visa extension whilst in Thailand. Would this work, or is there a better way to do things. I have never overstayed or had any previous issues with Thai immigration in the past. Thanks for any help that can be given.