Here are some remedies for the problems related to planets.

Surya
For Surya or Sun related troubles and during the dasa or antardasa of sun:
 

1. Worship the ruling deity Lord Shiva
2. Recite Aditya Hrudayam (stotra) daily or Gayatri Mantra daily.
3. Japa of Sun's moola mantra:
   "Om hram hreem hroum sah suryaya namah",
   6000 times in 40 days.
4. Recite the surya stotra:
   Java kusuma sankasam kashyapeyam mahadutim
   Tamorim Sarva paapghnam pranatosmi Divakaram
5. Charity: Donate wheat, or sugar candy on Sunday.
6. Fasting day: Sundays.
7. Do Rudrabhishekam on Sunday.
8. Rudraksha: Wear Ekamukhi or 12 mukhi Rudraksha

Chandra
For Chandra or Moon related problems and during the dasa or antardasa of Moon:
 

1. Worship the ruling deity Gouri.
2. Recite Annapoorna stotram.
3. Japa of Moon's moola mantra:
   "Om shram sreem shraum sah chandraya namah",
   10000 times in 40 days.
4. Recite the Chandra stotra:
   Dadhi Shankha tushaarabham ksheero darnava sambhavam
   Namaami shashinam somam shambhor mukuta bhushanam
5. Charity: Donate cow's milk or rice on Monday.
6. Fasting: On Mondays.
7. Pooja: Devi pooja on Monday.
8. Rudraksha: Wear 2 mukhi Rudraksha.

Kuja(Mangala)
For Kuja or Mars related problems and during the dasa or antardasa of Mars:
 

1. Worship the ruling deities Kartikeya and Shiva.
2. Recite Kartikeya or Shiva stotra.
3. Japa of the Mars mantra:
   " Om kram kreem kroum sah bhaumaya namah ",
   7000 times in 40 days.
4. Recite the Mangala stotra:
   Dharani garbha sambhutam vidyut kanti samaprabham
   Kumaram shakti hastam tam mangalam pranamamyaham.
5. Charity: Donate Masoor dal( red lentils) on Tuesday.
6. Fasting: On Tuesdays.
7. Pooja: Kartikeya pooja or Rudrabhishekha.
8. Rudraksha: Wear a 3 mukhi Rudraksha.

Kuja stotra :
Angarakoyamaschaiva sarvarogaapahaarakah
Nrishtekargaacha hartaacha sarvadevascha poojitah.
Lohito Lohitaakshascha samagaana Kripaakarah
Dharmatmajah Kujobhoumou bhumido bhuminam
Rakta maalyambaradharam shulashakti gadaadharah
Charbhujo yeshagato varadamcha dharaasutah
Mangalo bhumiputrascha runahartaa dhanapradah
Sthiraasano mahaakaayo sarvakaama phalapradam


Budha
For Budha or Mercury related problems and during his dasa and antardasa:
 

1. Worship Lord Vishnu.
2. Recite Vishnu sahasranama stotra.
3. Japa of the Budha beeja mantra:
   " Om bram breem broum sah budhaya namah" ,
   17000 times in 40 days.
4. Recite the Budha stotra:
   Priyangu Kalika Shyaamam Roopena Pratimam Budham
   Soumyam Soumya gunopetam tam Budham Pranamamyaham.
5. Charity: Donate green Moong dal on Wednesday.
6. Fasting: On Wednesdays.
7. Pooja: Vishnu pooja.
8. Wear a 10 mukhi Rudraksha.

Guru
For Guru or Jupiter related problems and during the dasa or antardasa of Guru:
 

1. Worship Lord Shiva.
2. Recite Sri Rudram.
3. Japa of the Guru beeja mantra:
   " Om jhram jhreem jroum sah gurave namah " ,
   16000 times in 40 days.
4. Recite the Guru stotra:
   Devanam cha rishinam cha Gurum kaanchan Sannibhaam
   Buddhi bhutam Trilokesham tam namaami Brihaspatim.
5. Donate: Saffron or turmeric on thursday.
6. Fasting: On Thrusdays.
7. Pooja: Rudrabhishekam.
8. Wear a 5 mukhi rudraksha.

Shukra
For Shukra or Venus related problems and during the dasa or antardasa of Venus:
 

1. Worship Durga Devi.
2. Recite Shree Sooktam or Devi stuti or Durga chalisa.
3. Japa of Shukra beeja mantra:
   " Om dram dreem droum sah shukraya namah ",
   20000 times in 40 days.
4. Recite the Shukra stotra:
   Hima kunda mrinalaabham daityanam paramam gurum
   Sarv shastra pravaktaram bhargavem pranamamyaham
5. Donate clothes to a lady on Friday.
6. Fasting: On Fridays.
7. Pooja: Durga Devi pooja.
8. Wear a 6 mukhi Rudraksha.

Sani
For Sani or Saturn related problems and during the dasa or antardasa of Shani:
 

1. Worship Lord Hanuman or Lord Siva.
2. Recite Hanuman chalisa or any other Hanuman stotra.
3. Japa of Shani mantra:
   " Om pram preem proum sah shanaischaraya namah " ,
   19000 times in 40 days.
4. Recite the Shani stotra:
   Nelanjan samabhasam ravi putram yamagrajam
   Chaaya martand sambhutam tam namami shanaischaram
5. Donate a buffalo or black oil (sesame seeds) on Saturday.
6. Fasting: On Saturdays.
7. Pooja: Hanuman pooja or Siva Pooja
8. Wear a 14 mukhi Rudraksha.

For all Saturn related troubles the following Shani Shodasanama stotra of Dasharatha is an excellent remedy.
Konassanaischaromandah chhayaahridayanandanah
Maargandaja sudhaasouri neelavastraanjanadyutih
Abrahmanah kroora kroora karmaatangi grahanaayakah
Krishnodharmaanujah shantah shushkodara varapradah

Apart from this reciting the following dasanama stotra of Shani by Dasharatha near a Pepal tree is also a highly recommended one.
Konastha pingalobabhruh
Krishnoroudraantakoyamah
Souri, shanaischaro mandah
Pippaladishu sansthitah

Rahu
For Rahu related problems and during the dasa or antardasa of Rahu:
 

1. Worship Bhairava or lord Shiva.
2. Recite the Kalabhairav asthakam.
3. Japa of the rahu beeja mantra:
   " Om bhram bhreem bhroum sah rahave namah",
   18000 times in 40 days.
4. Recite the Rahu stotra:
   Ardha Kaayam maha veryam chandraditya vimardhanam
   Simhika garbha sambhutam tam rahum pranamamyaham.
5. Donate: Udad dal or coconut on Saturday.
6. Fasting on Saturdays.
7. Pooja: Bhairav or Shiva or Chandi pooja.
8. Wear An 8 mukhi Rudraksha.
9. One of the best remedies for rahu is reciting the first chapter of Durga Saptasati.

Ketu
For Ketu related problems and during the dasa or antardasa of Ketu:
 

1. Worship Lord Ganesha.
2. Recite Ganesha Dwadasanama Stotra.
3. Japa of the Ketu beeja mantra:
   " Om shram shreem shroum sah ketave namah " ,
   7000 times in 40 days.
4. Recite the Ketu stotra:
   Palasha pushpa sankaasham taraka graha mastakam
   Roudram roudratmakam ghoram tam ketum Pranamamyaham.
5. Donate: A black cow or black mustard seeds on Thursday.
6. Fasting: On Thursdays.
7. Pooja: Ganesh pooja.
8. Wear a 9 mukhi rudraksha.
9. A very good remedy for Ketu is the reciting of Shiva Panchakshari Stotra.