There are two most common methods one is doing istekhara with Tasbeeh if after reciting namaz and recite this dua:
‎دعای استخاره
‎اللَّهُمَّ إِنِّي أَسْتَخِيرُكَ بِعِلْمِكَ وَأَسْتَقْدِرُكَ بِقُدْرَتِكَ، وَأَسْأَلُكَ مِنْ فَضْلِكَ الْعَظِيمِ، فَإِنَّكَ تَقْدِرُ وَلاَ أَقْدِرُ وَتَعْلَمُ وَلاَ أَعْلَمُ وَأَنْتَ عَلاَّمُ الْغُيُوبِ، اللَّهُمَّ إِنْ كُنْتَ تَعْلَمُ أَنَّ هَذَا الأَمْرَ (ضرورت را تان را در این قسمت ذکر کنید) خَيْرٌ لِي فِي دِينِي وَمَعَاشِي وَعَاقِبَةِ أَمْرِي فَاقْدُرْهُ لِي وَيَسِّرْهُ لِي ثُمَّ بَارِكْ لِي فِيهِ، وَإِنْ كُنْتَ تَعْلَمُ أَنَّ هَذَا الأَمْرَ شَرٌّ لِي فِي دِينِي وَمَعَاشِي وَعَاقِبَةِ أَمْرِي فَاصْرِفْهُ عَنِّي وَاصْرِفْنِي عَنْهُ، وَاقْدُرْ لِي الْخَيْرَ حَيْثُ كَانَ ثُمَّ أَرْضِنِي بِهِ
Then select some beads from the Tasbeeh if it came in odd numbers it means Ishtekhara is better in your favour and if beads comes in even numbers then it means one should not perform that act for which he has done Istekhara.
Another method is after reciting dua, open any page from the Holy Quran and at the right side page on the top whatever Ayat is written, if it’s meaning shows positive command then It means Istekhara is better otherwise it’s not good.
3 tareeqa eh hai ke Insan 2 Rakat namaz jaise subh ki nama Ada karta hai parhe fir wahi dua jo uper likhi hai parhe aur Allah per itmenon rakhe woh agar jis kam ke liye Istekhara kar rahe hain hamare Haqq main hoga to uske asbaad muhaiyya kar dega aur agar Haqq main nahin hai to bhi kisi sabab ki bina per kam aage nahin barhega. Ho sakta hai Insan Khwab bhi dekhe jismain use ilham ho jaye ke is kam ka karna munasib hai ya nahin.