Turn the intention into a sentence containing an action, a context and a visible result, then test it with a practice session small enough to finish in one sitting.
Why a vague intention stalls
'Get better at' describes a change but not an activity. Spreadsheets cover formatting, formulas, charts, data cleaning and much more, so the phrase leaves you to choose among dozens of possible starting points. That choice is tiring, and tiredness is a common reason a goal sits untouched.
A vague goal also gives you no way to tell whether you have succeeded. If you spend an hour watching a tutorial, have you improved? Without a visible result, it is hard to feel progress, and harder to decide what to do next.
Add an action, a context and a visible result
Start with a verb that describes something you can do: build, write, sort, summarise, explain. Then attach a real situation, because skills stick better when they are tied to something you care about. Tomás tracks his household spending, so a monthly expenses sheet is a natural setting.
Finally, say what will exist at the end. A finished sheet, a chart, a one-page summary or a checklist all count. If another person could look at the result and see what you did, the goal is concrete enough.
Shrink it to a first practice
Even a good goal can be too large for one session. Ask what the smallest piece is that would still teach you something. For Tomás, that is one category of one month, not the whole year.
Set the first practice so that it can fail usefully. If the formula returns an error, you have learned where to look next. A small test that fits in half an hour is far easier to start than a plan that needs a free weekend.
See the idea
in a real situation.
Tomás has kept 'get better at spreadsheets' on his to-do list for months. Every time he reads it, he cannot tell what the first move would be, so he does something easier instead.
Get better at spreadsheets.
By the end of next week, I will build a monthly expenses sheet from my last three bank statements, using SUMIF to total spending by category and adding one chart, and I will check it by comparing each spending-category total with an independently checked sum of the same outgoing transactions; a closing account balance is a different figure. First test: today, for 25 minutes, enter one month of transactions and write a SUMIF for the groceries category only.
↗The verb 'build' and the named formula show exactly what practice looks like, so there is no decision to make before starting.
↗The context, his own bank statements, supplies real data and a reason to care about the answer.
↗Checking each category total against an independently calculated sum of the same outgoing transactions provides a relevant check. A closing account balance is not the same as a spending-category total.
Write your goal as one sentence with an action, a context and a visible result, then book thirty minutes for the first test.