Core practical: identifying the ions in unknown salts

Flame test (solids): clean a nichrome wire loop by dipping it in hydrochloric acid and holding it in a blue Bunsen flame until it gives no colour. Dip it in the solid and hold it in the flame.
Sodium hydroxide test (solutions): dissolve the salt in distilled water. Add a few drops of dilute sodium hydroxide solution and look for a precipitate. If it is white, add more (excess) sodium hydroxide.
Ammonium ions: add sodium hydroxide solution and warm gently. Ammonia gas is given off, which turns damp red litmus paper blue.

Carbonate, CO₃²⁻: add dilute acid. Bubbles of carbon dioxide are given off, which turn limewater milky.
Sulfate, SO₄²⁻: add dilute hydrochloric acid, then barium chloride solution. A white precipitate (barium sulfate) shows a sulfate. The acid is added first to remove carbonate ions, which would also give a white precipitate.
Halides: add dilute nitric acid, then silver nitrate solution. Chloride, Cl⁻: white precipitate. Bromide, Br⁻: cream precipitate. Iodide, I⁻: yellow precipitate. Nitric acid is used, not hydrochloric acid, because hydrochloric acid adds chloride ions.

Each test must be unique: it gives a result for only one ion, so you can tell which ion is present.
Do one test for the cation and one for the anion, then combine them. For example, a green precipitate with sodium hydroxide and a white precipitate with hydrochloric acid and barium chloride means iron(II) sulfate.
A flame test cannot identify the metal ions in a mixture, because one colour can hide another.
Safety: wear eye protection. Barium chloride is harmful, sodium hydroxide solution is an irritant and silver nitrate irritates and stains the skin, so wash off any splashes. Take care with the hot wire and the Bunsen flame.