If I didn’t have a homeopathic kit and wanted to start collecting remedies to make one or wanted a few essentials to take while traveling, these are the ones I would start with:
Aconite: shock; fear; panic; illness after exposure to cold air
Apis: bee stings; swelling; shingles; allergic reactions
Arnica: injuries; bruises; pain; healing after any injury or dental/medical procedure
Arsenicum album: food poisoning; diarrhea; asthma; anxiety
Belladonna: high fevers; sunburn; delirium
Bryonia: constipation; influenza; migraines; grumpiness
Calcarea carb.: malnutrition; fatigue; obesity; connective tissue disorders
Carbo veg.: indigestion; fainting; collapse; chronic fatigue
Gelsemium: stage fright; influenza; diarrhea; general feeling of low energy
Hepar sulph.: infections; abscesses, sore throat; ear infection; swollen glands
Hypericum: nerve pain; nerve injuries; spinal injuries; phantom pains
Ignatia: grief; depression; hysteria; compulsive behavior
Lachesis: sore throat; loss of voice; hemorrhages; varicose veins
Ledum: puncture wounds from bites, stings, etc; bruises; blood poisoning
Mercurius (sol. or vivus): infections of all kinds; sinusitis; swollen glands
Nat mur.: depression; allergies and chemical sensitivities; hay fever; constipation
Nux vomica: over –eating, drinking, work, etc; constipation; hemorrhoids; insomnia; addictions
Phosphorus: upper respiratory illnesses; laryngitis; bleeding; fear of thunderstorms
Pulsatilla: moody; weepy; PMS; pink eye; hay fever; heartburn
Rhus tox.: joint and muscle pain; low back pain; poison ivy; shingles; skin rashes
Ruta graveolens: injuries/soreness of tendons and ligaments; eye strain; hip pain
Silica: general infections; tooth decay; bone disease; TMJ; digestive disorders; food allergies
Sulphur: skin conditions; food allergies; digestive disorders; burning pains
Symphytum: sprains; fractures; broken bones (once set); hernia
Thuja: irritable bowel; herpes; warts; polyps; sinusitis
Of course, it is ideal in homeopathy to match the entire picture of symptoms that a person is displaying to the remedy that addresses the greatest number of those symptoms. However, in emergency situations, I have found that the remedies listed above cover a wide range of symptoms. It is also helpful to purchase a complete homeopathic kit to have on hand.