There are numerous productivity frameworks and self-help methods dedicated to getting things done. The most important thing to tackle is making the priorities of different tasks clear. Otherwise you might end up focusing on wrong things and ending up not making meaningful enough progress.
Some things are obviously more important than others but even then ot might be tempting to so the easy tasks first. Starting off with such things have it's benefits. Getting the feeling of progress and accomplishment can give an energy boost to better take care of the bigger, more taunting tasks.
On the other hand getting the most challenging task out of the way early is also important. After that you can just relax and enjoy the "relaxing" rest of the day with easier tasks.
The hardest thing is deciding the priority of equally important tasks. If they all need ro be done anyway it's better to follow your own preference starting with the smaller, easier tasks first or just jump right in eating the frog.
Also important is to identify the tasks that are not worth doing, or those that can be delegated to others. In the end it all comes down to urgency and impact that can be easily visualized for example by using an Eisenhower matrix.