In principle, there are virtually no limits on what can be crafted by a player with the appropriate feats and sufficient (effective) caster level, time, and money. There are guidelines for creating arbitrary magic items which are not explicitly covered by the existing item lists.
The limits that Pathfinder provides are basically maximum bonuses that various items can grant (+5 enhancement to weapons/armor, +10 total bonus to weapons/armor, +6 bonus to abilities, and I think there's a limit to the skill bonus an item can grant, but I can't find it; it may have been a 3.5 limit).
One key thing to remember: the guidelines are guidelines; after using them to price an item, see how powerful similarly-priced items from books available in the campaign are, and adjust the final price or the item's power level (or both) 'til it matches.
There are a few general caveats to keep in mind with regard to crafting feats:
Crafting requires time. A player who has invested in crafting feats is likely to feel cheated if the campaign doesn't give him time to use those feats (I know I did). If this describes your campaign, consider talking to the GM about swapping the feat out for something that'll be more useful. If there are just one or two specific items that you'd like to make, it may be worth the GP to hire someone to make it rather than burning a feat.
Crafting most things requires a fair amount of workspace and random, assorted tools (the costs of which are generally negligible, unless they're Masterwork), and potent materials. If the campaign doesn't lend itself to maintaining a base of operation, crafting is going to be difficult or impossible. Scribing Scrolls is the biggest exception to that, as you can generally get away with a folding desk and some pens.
In addition to the material components of any spells which are required to craft the item, crafting needs its own set of materials. Frequently, these are vague and assumed to be relatively easy to obtain (ie., "spend the GP required, and the various bits and bobs are there for your use"). Depending on the particular item, campaign, and GM, finding materials may be a quest in itself. This isn't necessarily a bad thing, but it will cut down on the amount of crafting that the character can perform.
The system-based limits on what can be crafted are pretty minimal. The campaign- and GM-based limits are going to be much more relevant.
Work with your GM to stat and price items before you get too invested in them. Be prepared for the GM to want to bump the price up a bit.
Make sure you've got (or can acquire) the workspace and any special materials before you start crafting: remember, if you start working on a second thing before the first is finished, all of the progress you've made on the first thing is wasted (but, you can pause for as long as you'd like).