How to achieve that rustic look and feel:
Step 1:
You will need some pool acid to pickle the steel in preparation for the rusting process. But first a word of caution; you will need some PPE (Personal Protective Equipment) to safely work with the pool acid - it will burn your skin if you donít use chemical resistant cloves and even more important is the gasmask to prevent the inhalation of the toxic fumes. Now that I got that off my chest we can continue applying the acid with a paintbrush, make sure you thoroughly cover all he areas you want rusted.  
Step 2:
Donít pack the PPE away yet you will need it for this step as well. For this step you will need Hydrogen Peroxide 40% which can be bought at the chemist. Apply it to all the areas you want to rust, the oxidation or rusting will be instantaneous. The more cotes you apply the darker the rust will be and it will even get darker the hotter the metal is - so itís a good idea to do this on a hot sunny day.
How to achieve that weathered look on wood:
Step 1:
To give new wood that old weathered appearance you will need to make a special brew consisting of white spirit vinegar and a piece of steelwool. Leave it for a couple of days to get acquainted with each other before using it. Remember to get the PPE before you start, apply the solution to the wood with a paintbrush and leave it in the sun for an hour or two.
Step 2:
Dilute white PVA paint with water (1:1) and apply it with a paintbrush and leave to dry and the sand it down until you can see the basecoat you applied in step 1 until you have your desired look. Or you can wipe the paint off with a cloth before it dries, you need to experiment a bit to see what works best for you. 
The frame on the left is the look after step 1 and the one on the right is after step 2 - the cloth method was used.