Umar ibn Al-Khattab (may Allah be pleased with him) said, "Bring yourself into account before you are brought into account. Weigh your actions before they are weighed." (Ya Ayya Al-Walad by Imam Ghazali)
The best time to make up fasts is winter or when the days are short. You can have breakfast and miss dinner then eat at four pm! (Please check your local times!)
If you cannot make up the prayers and fasts because of illness then pay the fidya for the fasts. If you do not have the money to pay for the missed fasts then seek forgiveness and pay when or if you have the money (Tahfat Al-Muluk). Even having the intention to make them up, when you cannot, is good.