Here are two mnemonic techniques which help memorize (sequential) lists. In principle, these two techniques are similar to the Loci system but really need the lists to be in sequence, whereas the Loci method is more "random access".
Examples of sequential lists are shopping lists, task lists, equations, layers in a technical architecture (e.g. OSI), and so on - any list where the order is important.
The Link Mnemonic
The Link mnemonic works by associating each pair of items in the list with the following item. The concept is very similar to the singly-linked list used in computer science.
The items are linked with vivid associations, marked with arrows in the above picture. These associations contain both items to be connected. This way a sequential ordering is created from item 1 to item 2, and from item 2 to item 3, and so on. The associations help to remember eventually the whole list, in order.
An Example of the Link Mnemonic
Suppose you need to memorize the following list: milk, sugar, diapers, beer, fish sticks.
To use the link mnemonic in memorizing the list, you would associate "milk" with "sugar", then "sugar" with "diapers", then "diapers" with "beer" and finally "beer" with "fish sticks".
For "milk" and "sugar", you might imagine a cow opening a milk carton and pouring it to a deep plate, but out comes sugar instead of milk and the cow has a surprised look (and says "moo" for more effect)! Then, for "sugar" and "diapers", you could imagine a baby wearing a giant sugar cube instead of wearing a diaper. Proceed this way, for each pair, until the whole list is completely memorized. The more surrealistic scenes you can picture, the better you remember your list.
To access the list, you have to start from the first item, i.e. "milk", and then proceed from that. Remember what "milk" was associated with ("sugar"), and then use that ("sugar") as the key to find the next item, and so on.
To bootstrap the list, if you think you cannot remember the first item, you can associate the shop door or parking lot with "milk".
After memorizing the sequence as described above, it will (conceptually) be something like the following image. Basically you just add associations to the original list to tie the items together. For example, "milk" and "sugar" were linked together with associating them both somehow with a cow.
Some lists (such as the shopping list used in the example) can be rearranged for easier learnability. For example, if it's a hot day you could start with a more memorable "beer" and proceed to build the list from that.
The Story Mnemonic
The Story mnemonic is kind of an extended Link mnemonic. Instead of associating an item in the list with the next item, you expand the association to form a "fluid" story.
An Example of the Story Mnemonic
Let's use the same shopping list as above; milk, sugar, diapers, beer, fish sticks.
To begin, you associate "milk" with "sugar". Then, you associate "sugar" with "diapers", etc. while weaving a fluid story to connect your association to the next association. That is, you are not just creating pair-wise links as with the Link mnemonic, but creating whole stories instead.
An example (which makes sense to me, your story will be completely different) would be the following story: "A cow is pouring milk from a milk carton. But out comes a baby, wearing a glittering sugar cube instead of a diaper. The cow is very shocked, and takes a beer can to calm down. As the cow opens the beer can, there is a loud noise and different kinds of fish and drumsticks start raining from the sky."
When you memorize a list with the Story mnemonic, you must vividly picture the whole story happening, as if watching a movie inside your head. The more dream-like and surreal you can make it, the better you will remember it (thus aiding your recall of the list).
The Link and Story mnemonics can be used to memorize lists with sequential information. Depending on the items in the list, the Link mnemonic can be faster to use when memorizing. But the Story mnemonic is more robust, as you will be forming a fluid dream-like story (with more redundancy) to connect your associations for each list item.
Also, if you are really bad in visualizing things, but are good with verbal things (e.g. remember well what you hear) then these two methods may work better for you than the Loci system. You can speak your associations out aloud instead of visualizing.