I don't have answer on accurately estimating the resources but I can tell you what I do to save the cost.
I have personal pay-as-you-go subscription and i never let the cost go beyond 500-1000 INR
Before creating any new Azure service I try to understand how much this will cost me. Resources like Azure storage, ADLS Gen2, ADF doesn't cost much. It cost more when you upload more files or trigger pipelines multiple time or use Dataflow in ADF
If I use ADB, I terminate the cluster as soon as work is done.
If any service is costing me more like Azure SQL DB or Azure Synapse SQL which are charged per month, I delete them as my work is done.
Monitor the cost by resources from Cost management. I set up alerts like send me email when total cost cross 200, 300, 400 INR.
Please don't forget to Accept Answer and Up-vote if the response helped -- Vaibhav